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COPyKIGtlT DEPOSIT. 



FERTILIZERS 



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FERTILIZERS 



THE SOURCE, CHARACTER AND COMPOSITION OF 

NATURAL. HOME-MADE AND MANUFACTURED FERTILIZERS; 

AND SUGGESTIONS AS TO THEIR 

USE FOR DIFFERENT fcROPS AND CONDITIONS 



BY 

EDWARD B. yOORHEES, A.M. 

Director of the New Jersey Agricultural Experiment Stations, and 
Professor of Agriculture in Rutgers Collepe 



NINTH EDITION 



THE MACMILLAN COMPANY 

LONDON: MACMILLAN & CO., Ltd. 

1907 

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COPTRIGHT 1898 

Sy EDWARD B. VOORHEES 



Set np and electrotj-ped November, 1808 

Reprinted with corrections January, 1900 

January and February, 1902, February, 190" 

August. 1904. August, 1905, January, 1907 

March, 1907 



6Rount ©Ifaaant Pte0» 

.1. Horace McFarland CojiPAXT 
HAERiSBrRO • Pennsylvania 



\ 



PREFACE 

There is no question as to the desirability of 
the use of commercial fertilizers on most farms, 
though the methods now generally practiced are such 
as to indicate tlie very great need of a better under- 
standing of what the functions of a fertilizer are, 
of the terms used to express their composition and 
value, of the kind that shall be used, and the time 
and method of application for the different crops 
under the varying conditions that exist. 

In the preparation of this book, therefore, it has 
been the aim of the author to point out the under- 
lying principles and to discuss, in the light of our 
present knowledge of the subject, some of the 
important problems connected with the use of fer- 
tilizer materials. The subject is a large one when 
considered in all its bearings, and much must nec- 
essarily be omitted in a book intended for the 
general reader as well as the student. 

The author appreciates keenly his limitations, 
owing to the lack of definite knowledge on many 
vital points ; yet it seems that at this time, when 

(r) 



VI PUKKACK 

the iuvestigations of the experiment stations are 
beginning to be regarded as important educational 
factors, and when these institutions are more than 
ever prepared to study the fundamental principles 
which underlie the various processes involved in 
plant nutrition, the practical man should have a 
clear understanding of what is now known, in order 
that he may be prepared to accept and use that 
better knowledge which will undoubtedly be pro- 
vided for him in the near future. 

E. B. V. 

Nbw Brunswick, N. J., September 20, 1898. 



CONTENTS 



CHAPTER T 

PAOXS 

The Natural Fertility op the Soil, and Sources of 

Loss OF THE Elements of Fertility 1-20 

Soil Fertility — Chemical elements needed In plant 
growth— Fertility as influenced by water, climate and 
season — The influence of physical character of soil — 
Location of soil qualifies the term " fertility "— Practical 
fertility is usable potential fertility 2-7 

What Becomes of Our Fertility 1 7-8 

Sources of Natural Loss of Nitrogen- Importance of 
careful culture — Loss of nitrogen by drainage — Escape of 
nitrogen into the atmosphere 8-12 

The Natural Loss of the Mineral Elements- Losses 
due to mechanical means 12-14 

Artificial Losses of Fertility— A comparison of the 
prices received for the fertility elements in different 
crops — Fertility content of cereals and vegetables- Irra- 
tional farm practice — Losses in manures 14-20 



CHAPTER n 

The Function of Manures and Fertilizers, and thk 

Need of Artificial Fertilizers 21-37 

The Essential Elements of Fertilizers 21 

Natural Manures and Artificial Fertilizers 22 



(vii) 



vin 



CONTENTS 



PAOES 

Direct and Indirect Effect of Manures 2M 

Unavailable and Available Plant-food 24-26 

Danger of Loss from the Use op Soluble Plant-food.. 26 
The Usefulness of a Fertilizer Constituent Does not 

Depend Upon Its Original Source 27 

Use of Fertilizers 28, 29 

The Need of Artificial Fertilizers — The cost of produc- 
tion per unit of income is increased — A greater demand for 
special crops — Farm manures are inadequate — The growing 

importance of fruit-growing 30-35 

Will It Pay to Use Fertilizers? 35-37 

CHAPTER HI 

Nitrogenous Fertilizers 38-r)7 

What Is Meant by Form of Nitrogen ? W.) 

Dried Blood 40, 41 

Dried Meat or Meal, Azotin, Ammonite, or Animal 

Matter 41 

Hoof Meal 42 

Dried and Ground Fish, or Fish Guano 42 

King Crab 43 

Tankagk 43, 44 

Garbage Tankage 44 

Low-gkads Nitrogenous Products — Leather meal— Wool 

and hair waste 45 

Vegetable Nitrogenous Products— Cotton-seed meal- 
Linseed meal— Castor pomace 46 

Natural Guanos 47-49 

Ammonia Compounds— Sulfate of ammonia 50,51 

Nitrate Nitrogen — Nitrate of soda 52 

The Relative Availability op the Different Forms of 

Nitrogen — Conditions which modify availability 53-57 



CONTENTS IX 



CHAPTER IV 



PAGES 



Phosphates— Their Sources, Composition, and Rela- 
tive Value 58-77 

Phosphate of Lime, or Bone Phosphate— Animal Bone— 
Raw bone— Fine bone— Boiled and steamed bone — Bone 
tankage — Other organic products — Bone-black, or animal 
charcoal — Bone ash 59-66 

Mineral Phosphates— South Carolina rock phosphates- 
Florida phosphates — Canadian apatite — Tennessee phos- 
phate—Iron phosphate, or Thomas phosphate powder— 
Phosphatic guanos 66-71 

Phosphates as Sources op Phosphoric Acid to Plants— 
The influence of source of phosphate upon availability — 
Influence of fineness of division — The character of soil as 
a factor influencing availability— Influence of kind of 
crop— General considerations 71-77 



CHAPTER V 

Superphosphates— Potash 78-98 

Insoluble Phosphoric Acid 78 

Soluble Phosphoric Acid 79 

Reverted Phosphoric Acid 80 

How Superphosphates are Made — The difference in the 
superphosphates made from the different materials — Sol- 
uble phosphoric acid identical chemically, from whatever 

source derived 80-83 

Phosphates and Superphosphates are not Identical... 83-87 

Double Superphosphates 87 

Chesiical Composition op Superphosphates— Well-made 
superphosphates contain no free acid — Phosphoric acid 

remains in the soil until taken out by plants 88-91 

Potash Salts — The importance of potash as a constituent 
of fertilizers — Forms of potash — Kainit—Sylvinit— Muri- 
ate of potash — High-grade sulfate of potash— Double 
sulfate of potash and magnesia— Fixation of potash 92-98 



X CONTENTS 

(CHAPTER VI 

PAOXS 

Miscellaneous Fertilizing Materials 99-123 

Tobacco Stems and Stalks 100, 101 

Crude Fish Scrap lOl-lO:; 

Wool and Hair Waste 103 

Poultry and Pigeon Manures 104 

Sewage lOn 

xMucK AND Peat 106 

King Crab, Mussels and Lobstkr Shells 107 

Seaweed 10« 

Wood Ashes and Tan-bark Ashes 109-111 

Coal Ashes Ill 

Cotton-hull Ashes Ill 

Marl 112 

Lime 1 i;!-l IG 

Agricultural Salt Hti 

Powder ^VASTB 117 

CAREEN Manures — "Nitrogen gatherers " and "nitrogen cou 
sumers"— The most useful crops — Green manure crops that 

consume the nitrogen in the soil 117-12.J 

CHAPTER VII 

Purchase of Fertilizers 124-148 

Standard High-grade Materials 125, 126 

Fertilizing Materials Variable in Composition 126, 127 

High-grade and Low-oradk Fertilizers — The "unit" 
basis of purchase — The "ton" basis of purchase — The 
necessity of a guarantee— Laws alone do not fully protect — 
Method of statement of guarantee sometimes misleadiug — 
Discussion of guarantees — The advantages and disadvan- 
tages of purchasing raw materials and mixed fertilizers... 127-141 
Home Mixtures — Formulas — A low-grade feriilizt r — The cost 

of handling "make-weight " 141-147 

General Advice 147-148 



CONTENTS XI 

CHAPTER VIII 

PAGKS 

Chemical Analyses of Fertilizers 149-166 

Thk Interpretation of an Analysis 149-152 

The Agricultural Value of a Fertilizer 152-15:t 

The Commercial Value of a Fertilizer— Schedule of 

trade values adopted by experiment stations for 1898 153-1C2 

Calculation of Commercial V^alues 162-164 

The Uniformity of Manufactured Brands 164-166 

CHAPTER IX 
Methods of Use of Fertilizers - . 167-190 

Conditions Which Modify the Usefulness of Fer- 
tilizers— Derivation of soil a guide as to its possible 
deficiencies — Physical imperfections of sandy soils — Physi- 
cal imperfections of clay soils — The influence of previous 
treatment and cropping— The influence of character of 
crop — The kind of farming, whether "extensive" or 
« intensive " 167-177 

Plants Vary in Their Power of Acquiring Food— Char- 
acteristics of the cereal group— Characteristics of grasses 
and clovers — Root crops — Market-garden crops — Fruit 
crops 177-182 

Systems of Fertilizing Suggested— A system based upon 
the specific influence of a single element — A system based 
upon the necessity of an abundant supply of the min- 
erals—A system based on the needs of the plants for the 
different elements as shown by chemical analysis — A 
system in which the fertilizer is applied to the "money 
orop" in the rotation — An irrational system 182-190 

Summary 190 

CHAPTER X 

Fertilizers for Cereals and Grasses 191-213 

Experiments to Determine the Lacking Element— A 

scheme for plot experiments— Results that may be attained. 193-198 



Xll CONTENTS 

PAOKS 

The Importance op System in the Use of Fertilizers— 
Indian corn exhaustive of the fertility elements — Oats- 
Wheat— Clover— Timothy— A gain of fertility by the sys- 
tem—The necessity of adding more plant-food than is 
required by a deliuite increase in crop — The system should 

be modified if no farm manures are used 198-207 

Fertilizers for a Single Crop Grown Continuously ... 208-211 

Fertilizers for Meadows 211 

Will This System of Feutilizino Pay? 212,213 



CHAPTER XI 

Potatoes, Sweet Potatoes, Tomatoes and Sugar Beets. 214-240 

Fertilizers for Potatoes, Early Crop— The time and 
method of application — The amount to be applied — F'orm of 
the constituents 215-220 

Late Potatoes 220, 221 

Sweet Potatoes— Fertilizer constituents contained in an 
average crop — The application of fertilizers 221, 221) 

Tomatoes— Field experiments with fertilizers for tomatoes- 
Fertilizers for the early crop for different conditions of 
soil — The use of f(.>rtilizers with yard manures — Fertilizers 
for late tomatoes 226-235 

Sugar Beets— The demands of the crop for plant-food— The 
influence of previous deep cultivation of soil 235-240 



CHAPTER XII 
Greek Forage Crops 241-261 

Maize (corn) forage— Silage corn — ^V'heat and rye forage- 
Spring rye— Oats — Oats and peas — Barley and peas -Millet. 

Clovers and Other Legumes— Cow pea and soy bean- 
Alfalfa, or Lucerne— Need of lime for legumes— Scheme of 
soiling crops 249-257 

Root Crops — Fertilizers for fodder beets, sugar beets and 
carrots — Turnips, Swedes and rape 257-261 

Tdbkr Crops 261 



CONTENTS XUl 
CHAPTER XIII 

PAGES 

Market -GARDEN Crops 262-281 

The Yield and Quality Dependent upon Continuous 

AND Rapid Growth 262-264 

Asparagus — The use of salt— Fertilizers that have proved 

nseful— A basic fertilizer for market-garden crops 264-269 

Peas and Beans 269, 270 

Beets and Turnips 270-272 

Cabbage, Caulifloweb and Brussels Sprouts 272, 273 

Cucumbers, Watermelons, Muskmelons, Pumpkins and 

Squashes 273-275 

Celery 275 

Sweet Corn 276 

Egg-plant, Spinach, Lettuce and Rhubarb 277-278 

Onions, Onion Sets and Scallions 278-281 

CHAPTER XIV 

Orchard Fruits and Berries 282-304 

Fruit Crops Differ from General Farm Crops 283 

The Specific Functions of the Essential Fertilizing 

Constituents 284 

The Character of Soil an Important Consideration . . . 285-287 

The General Character of the Fertilization 287, 288 

The Application of Fertilizers for Fruits 289 

The Fertilization of Apples and Pears — The amounts 

to be applied 289-294 

Peaches — The need of fertilizers — Methods of fertilization.. 294-299 

Plums, Cherries and Apricots 299 

Citrous Fruits 299 

Small Fruits in General 300 

Strawberries 301 

Raspberries and Blackberries 302 



XIV CONTENTS 

PAOIS 

Currants and Goosebkkries 303 

Grapks 303, 304 



CHAPTER XV 

Fertilizers b'or Various Special Crops 305-327 

Cotton — Fertilizers for cotton — Formulas for cotton ferti- 
lizers-Method of application 305-312 

Tobacco— The influence of fertilizers upon the quality of 
the crop- The conclusions from Connecticut experi- 
ments—Form of the constituents — Amounts to apply 312-317 

Sugar-Cane — The needs of the plant as indicated by the 
Louisiana experiments- The application of fertilizers 317-:^21 

Miscellaneous Crops— Sorghum — Buckwheat— Peanut- 
Roses and other flowering: plants— Lawn i^rasses- 
Forcing-house crops 321-327 



FERTILIZERS 



CHAPTER I 



NATURAL FERTILITY OF THE SOIL, AND SOURCES 
OF LOSS OF THE ELEMENTS OF FERTILITY 

There is no one question of greater importance to 
the farming industry than that of soil fertility. In 
order that the industry may be successful, it is not 
enough to produce crops ; it is necessary that their 
production shall result in a genuine profit. That is, it 
is not enough to produce crops which bring more than 
they cost in the way of labor and manures, without 
taking into consideration the effect of their growth 
upon the future productive capacity of the soil. The 
relation of the outgo and income of the fertility ele- 
ments is an important factor in determining profits, 
and must be considered. The farmer who secures 
crops that bring more than they cost, and who, at the 
same time, maintains or even increases the productive 
capacity of his soil, is, other things being equal, the 
broadly successful farmer. Many farmers are able to 
accomplish this object because of the knowledge they 
have acquired through long years of experience, rather 
than because they possessed in the beginning of their 
work a definite knowledge of the fundamental princi- 
A (1) 



2 FERTILIZERS 

pies involved iu crop production, and upon the ob- 
servance of which their success depended. One of 
the first needs, therefore, in the use of commercial 
fertilizers is a more or less definite knowledge of what 
constitutes fertility, and of the principles which under- 
lie crop production. 

SOIL FERTILITY 

The full meaning of the term "soil fertility" is not 
easily expressed, since many conditions are involved, 
all of which exercise more or less influence. The po- 
tential fertility, which is measured by the total content 
of the food elements contained in a soil, is made 
practicable, or usable, in proportion as the conditions 
are favorable. The more important of these influenc- 
ing conditions are here briefly discussed. In the first 
place, it is of the utmost importance that a soil should 
contain those elements found in the plant ; hence, it is 
almost self-evident that a fertile soil must contain a 
maximum quantity of those particular elements or 
constituents which are removed from the land in 
maximum amounts by the crops grown. The removal 
of crops rapidly exhausts the soil of these elements, 
and finally reduces the quantity contained in the soil to 
so low a point as to make profitable cropping impossible. 

Chemical Elements Needed in Plant Orowfh 

Careful studies and experiments have shown that 
plants actually take from the soil at least ten chem- 
ical elements which are required for their normal 



THE CHEMICAL ELEMENTS NEEDED 3 

growth and development: viz., nitrogen, potassium, 
phosphorus, magnesium, sulfur, sodium, iron, ehlorin, 
silicon and calcium. Yet the number liable to rapid 
exhaustion is limited in many cases to three, and at 
most to four, which are, nitrogen, phosphoric acid 
(phosphorus), potash (potassium), and lime (calcium), 
the latter only in exceptional cases. These are liable 
to be exhausted because they exist in larger amounts 
than the others in the plants that are grown, and in 
smaller amounts than the others in even the most fer- 
tile soils. It has also been proved that it is the one 
element of these which exists in the smallest amount 
which measures the crop -producing power, or fertility, 
in this respect, as one element cannot substitute or 
exert the full functions of another. That is, there 
may be a relative abundance in the soil of potash and 
of phosphoric acid, but practically no nitrogen, in 
which case good crops of cereals, for instance, could 
not be grown, because no other element can substitute 
the nitrogen required by the plant, and it can be 
obtained by it from no other source than the soil ; and 
the soil, for all practical purposes, is quite as unpro- 
ductive, lacking in productive fertility, as it would be 
if it contained much smaller amounts of the mineral 
elements mentioned, and thus be poorer in potential 
fertility. 

Fertility as Influenced by Water, Climate and 
Season 

In the second place, there are soils that are so rich 
in all of these elements that if productiveness depended 



4 FEBTILIZERS 

upon them alone, maximum crops might be grown for 
centuries without exhausting them, while actually they 
are now incapable of producing a single profitable crop 
of cereals, grasses, fruits, or other products of the farm, 
because certain other conditions which are essential, in 
order to bring them into activity, are absent. For 
example, it may be that water, which is absolutely 
essential both for the solution of these food elements 
in the soil, as well as for their distribution in the plant 
after they have been acquired, cannot be obtained, or 
that the temperature of the soil and of the surrounding 
air is either too low or too high, thus preventing or 
interrupting the progress of those changes which must 
go on, both in the soil and in the plant, in order that 
normal growth and development may be accomplished. 
With a full supply of the fertility elements in the soil, 
the climatic and seasonal conditions exert an important 
influence upon its productive power. 

It is evident, therefore, that the chemical elements 
of fertility in themselves are not sufficient to constitute 
what we understand by the term. Fertility is not 
measured by them alone ; associated with them there 
must be other conditions. That is, while crops cannot 
be grown without these elements, it is the conditions 
which surround them that, in a large degree, deter- 
mine the power of the crop to secure them. 

The Influence of Physical Character of Soil 

In the third place, the physi-al character of a soil 
is also a factor in determining actual fertility. This 



LOCATION QUALIFIUS FERTILITY 5 

has re^rence, first, to the original character of the 
rocks from which the soil particles were derived, 
whether hard and dense in their mineral character, thus 
resisting the penetration and the solvent effect of air 
and water and other agencies, or whether soft and 
friable, and freely permitting their entrance and ac- 
tion ; and secondly, whether, in the formation of the 
soil, the particles were so fine and so free from vege- 
table matter as to settle in hard and compact masses, 
impervious to water, air and warmth ; or whether they 
were coarse, and not capable of close compaction, thus 
giving rise to an open and friable soil, freely admit- 
ting the active natural agencies, such as we find to be 
the case in sandy soils. In addition to these properties 
of soils, which have a distinct place in determining 
fertility, there are many other minor ones which to- 
gether constitute what is understood as "condition." 

Location of Soil Qualifies the Term " Fertility " 

Furthermore, fertility, even in this true sense, may 
be useless because of the location of the soil which 
possesses it. For example, there are many places on 
this continent where sugar -producing plants will grow 
and develop perfectly, since the soils are very rich 
in the fertility elements, and since the surrounding 
conditions are most favorable for their culture, yet, 
because of their location, it is unprofitable to grow 
them for the manufacture of sugar. In the first 
place, the soils are so situated as to make it impos- 
sible, or at least impracticable, to provide the means 



t) FERTILIZERS 

necessary for converting the sugar- producing crop 
into actual sugar, and, in the second place, even if 
it were possible to do so, the great distance from 
shipping stations to markets so increases the cost of 
transportation as to make it unprofitable to compete 
in the market with the crops grown upon lands pos- 
sessing true fertility in a lower degree. 

Practical Fertility is Usable Potential Fertility 

Practical fertility is, therefore, dependent upon 
many conditions, and fortunately our own country 
possesses it in a marked degree ; that is, the utility 
of the potential fertility, as represented by the total 
mineral content of our soil, is such as to make us 
one of the greatest agricultural nations in the world, 
both in the quantity and variety of products grown. 
Our soils possess the essential elements in lavish 
amounts, and our climatic and seasonal conditions 
are such as to permit of their readj' conversion into 
a wide series of valuable products, and our location 
and facilities for handling and distributing our staple 
crops are such as to enable us to compete in any 
market of similar commodities. 

Notwithstanding the truth of this general state- 
ment, it is also true that in certain sections of our 
country profitable crops cannot be gi-own without the 
addition of commercial fertilizers, because the soils 
are either naturally poor, or they have become par- 
tially exhausted of their plant -food elements. That 
is, the amounts that become available to the plant 



WHAT BECQMJSS OF FEBTILITT / 

through the growing season are not sufficient to 
enable the plant to reach a maximum development, 
though other conditions are perfect. 

Our future progress depends, therefore, upon how 
well we understand and applj' the principles which 
are involved, both in the conservation and use of the 
fertility stored up in our soils, and in the use of 
purchased fertility ; and in this connection it is im- 
portant to consider the sources of loss of the essential 
fertility elements, or those which in the beginning 
measured our capabilities in crop production. 

WHAT BECOMES OF OUR FERTILITY ? 

Since fertility is dependent upon so many con- 
ditions, or, in other words, since the essential elements 
of fertility are dependent upon their utility, and since, 
in this sense, fertility is largely determined by natural 
conditions, it is pertinent to inquire, first, whether 
under our present systems of management, or mis- 
management, of the land, it is suffering any natural 
loss of fertility. As already pointed out, the most 
important function of fertility is to furnish nitrogen, 
phosphoric acid and potash, and since the content of 
these in our soil, together with the knowledge we 
have as to their use, measures, in a sense, our pros- 
perity as an agricultural people, the possibilities of 
losing them from the soil is a matter of national con- 
cern, and is of vital interest to individual farmers, 
who, in the aggregate, make up that part of the 
nation directly affected by the results of such loss. 



8 FERTILIZERS 

It would, perhaps, be possible, by a careful chemical 
survey of our soils, to determine both the actual and 
potential fertility of our entire country, and this 
knowledge, together with an accurate measure of the 
intelligence exercised in its use, would enable a predic- 
tion as to our future development, if present methods 
were continued. That is, whether our land would 
become barren and worthless, as has been the case 
in many older countries which at one time were quite 
as productive, or whether it would constantly increase 
in productiveness, even with continuous and profitable 
cropping, — though, as already pointed out, the present 
barrenness or sterility of a country formerly fertile 
may not be due entirely either to the natural or to 
the artificial loss of these constituents. 

SOURCES OP NATURAL LOSS OF NITROGEN 

Of the essential constituent elements, nitrogen is, 
in one sense, of the greatest importance; first, because 
it is the one that is more liable to escape than the 
others, and secondl3% because it is more expensive to 
supply artificially than are the minerals. It is the 
most elusive of all the elements : to-day it may be 
applied to the soil, to-morrow it may be carried in 
streams to the ocean. It is also unstable — which is 
not the least valuable of its characteristics if properly 
understood; — to-day it is an element of the atmos- 
phere, to-morrow it is a constituent part of a grow- 
ing plant, the next day the same element may exist as 
an animal product, and the day following it may be 



NATURAL LOSS OF NITROGEN 9 

returned to the soil to feed tlie plant. It is more 
liable to escape than any of the others, because 
it is available as plant -food largely in proportion 
as it changes to a nitrate, and after it assumes 
that form it is seldom absorbed or fixed in the 
soil. Nitrogen in this form remains freely mov- 
able, and the probability of loss by leaching is 
increased in direct proportion to the lack of preven- 
tive measures used, or the presence of those conditions 
which favor leaching. The latter may be classified as 
follows: First, the amount and time of the rainfall; 
secondly, the absorptive and retentive power of the 
soil and subsoil, due to their mineral and physical 
character ; and thirdly, the amount of vegetable matter 
(humus) acquired by the soil, which retards the 
passage of water. While the amount and time of 
rainfall cannot be controlled, its effect upon our soils 
in this direction can be largely governed if proper 
attention is given to correcting the other conditions, 
and these may be largely modified, if not entirely 
controlled. In the matter of the absorptive and reten- 
tive power of soils, it has been shown that if they are 
well supplied with vegetable matter and carefully 
cultivated, they retain and hold the plant -food con- 
stituents in a much greater degree than if devoid of 
humus and improperly managed, and also that the 
drainage water from soils upon which crops are grow- 
ing seldom contains more than the merest trace of 
nitrates. The loss of nitrogen through the opera- 
tion of the forces of nature may, therefore, be 
reduced by the careful management of the soil. 



10 FEBTILIZEBS 

Importance of Careful Culture 

The presence of suitable amounts of vegetable 
matter, and good cultivation, are conditions that are 
within the power of all farmers to provide, though it 
is sometimes impracticable to keep the land contin- 
uously covered with a crop ; and sometimes it is 
thought that the loss incurred through leaching be- 
cause of the absence of a growing crop is more than 
balanced by the gain in other directions. For example, 
though losses of nitrates may occur, the gain in 
availability of the mineral constituents, phosphoric 
acid and potash, with the accompanying improvement 
in texture, due to the exposure of the soil to atmos- 
pheric influence, more than balances these losses, par- 
ticularly during the winter, with its wide changes of 
temperature. 

Loan of Nitrogeti hij Drainage 

It has been shown by carefully conducted experi- 
ments, both in this and other countries, that in a 
season of average rainfall the drainage waters carry 
away from one acre, from uncropped soils only fairly 
rich in plant food, as much as 37 pounds of nitrogen 
per year, while when continually cropped the drainage 
waters from the same soils contain practically no 
nitrogen. This difference in the loss of nitrogen 
under the two conditions may not seem a great matter 
at the first glance, but a careful study of the bearing 
of this loss in its relation to crop production shows 



LOSS OF NITROGJslN BY DRAINAGE H 

that it is really a serious matter. In the first place, 
the amount of possible loss annually is practically 
equivalent in nitrogen to the amount contained in two 
tons of timothy hay, or in one ton of either wheat, 
rye, oats, corn or buckwheat, quantities nearly double 
the average yield per acre of these crops throughout 
our whole country; and in the second place, that the 
nitrogen which is carried away by the drainage water 
is in the very best form for feeding the plant, or it 
would not have been lost, and thus its loss leaves the 
soil not only poorer in this constituent element, but 
poorer in the sense that the remainder of it in the 
soil is in a less useful form. 



Escape of Nitrogen into the Atmosphere 

Another source of natural loss of nitrogen is its 
escape from the soil as gas into the atmosphere. This 
is due to the oxidation of the vegetable matter, or to 
"denitrification," which takes place very rapidly when 
soils rich in vegetable matter are improperly managed. 
The possibilities of loss in this direction are strongly 
shown by investigations carried out at the Minnesota 
Experiment Station on "the loss of nitrogen by con- 
tinuous wheat raising."* The results of these studies 
show that the total natural loss of nitrogen annually 
was far greater than the loss due to the cropping. In 
other words, by the system of continuous cropping, 
which is universally observed in the great wheat 



^University of Minnesota Agricultural Experiment Station, Bulletin 53. 



12 FERTILIZERS 

fields in the Northwest, there were but 24.5 pounds 
of nitrogen removed in the crop harvested, while the 
total loss per acre was 171 pounds, or an excess of 
146 pounds, a large part of which loss was certainly 
due to the rapid using up of the vegetable matter by 
this improvident method of practice. Whereas, on 
the other hand, when wheat was grown in a rotation 
with clover, the gain in soil nitrogen far exceeded 
that lost or carried away by the crop. The continuous 
wheat- and corn -growing in the West, and of cotton 
and tobacco in the southern states, are responsible 
for untold losses in this expensive element of fertility, 
while in nearly every state of the Union, soils both 
rich and poor are suffering more or less from the 
effect of natural losses in this direction 

THE NATURAL LOSS OF THE MINERAL ELEMENTS 

In the case of the minerals, phosphoric acid and 
potash, which exist in fixed compounds in the soil, the 
actual losses are undoubtedly very much less than is the 
case with nitrogen, since only traces of these constitu- 
ents are ever found in solution in the drainage waters 
under ordinary circumstances; yet, because of the large 
quantity of water that passes through many of our 
soils, the total amount of these rendered soluble and 
carried away by this means is very great. Our great 
rivers carry in solution into the ocean tons upon tons 
annually of these elements of fertility, and it is an 
absolute loss, as there is no natural means by which 
these may be returned to the soil, as is the case with 



MECHANICAL LOSSES OF FERTILITY 13 

nitrogen; and it is true, as in the case of the former, 
that the soil is not only absolutelj^ poorer by virtue 
of the loss of its elements of fertility, but poorer 
in the sense that the immediate utility of those re- 
maining is reduced. These silent and unseen forces 
constantly at work are reducing the content of these 
constituents in our soils to an alarming degree, and 
it is because they are unrecognized forces that the 
disastrous results of their activity are not fully appre- 
ciated, and, consequently, the best means for restor- 
ing them are not used. 

Losses Due to Mechanical Means 

A serious loss of all of the fertility elements is 
also due to mechanical means. Aside from the amounts 
that the rivers of water are carrying in solution into 
the seas, immense amounts are carried in them in 
suspension. The results of this kind of loss are pain- 
fully evident ; in many of the southern states, and in 
sections where the forests have been removed and the 
land abandoned, the soils have been washed and 
gullied until not only the very best portions, but in 
some cases the largest portions, have been carried 
away. 

It is not, however, in the abandoned parts of 
the country alone that these mechanical losses of con- 
stituents are of importance — they are more or less 
apparent on every farm, and are measured by the 
methods of management. Soils that are allowed to 
lie bare and fully exposed to the storms of wind and 



14 FERTILIZERS 

rain througnout the larger portion of the j'ear suffer 
the greatest loss, while from those which, on the 
other hand, have crops growing during a large part 
of the year, and which hold the soil particles together 
and prevent their easy movement, the losses are re- 
duced in both the directions mentioned. The benefi- 
cial results derived from the use of good methods 
are cumulative ; the benefit is not only immediate, 
but continuous. 

ARTIFICIAL LOSSES OF FERTILITY 

In addition to these natural losses of fertility, there 
are the artificial losses of the constituents, or those 
due to the removal of crops. These, of course, neces- 
sarily accompany all farming operations, and, provided 
that in the removal and sale of the constituents in 
the form of crops, the farmer has received a fair 
price for them, they are entirely legitimate. 

The sale of farm products is really in the last 
analysis a sale of actual constituents, together with 
a certain portion of the " condition " of our land, 
which is not readil}^ measurable. That is, it is the 
constituents in the soil, together with the conditions 
surrounding it, that the farmer buys when he bujs 
land. If an acre of land, containing within the reach 
of the roots of the plant, say 3,000 pounds of nitro- 
gen, 5,000 pounds of phosphoric acid and 6,000 pounds 
of potash, sells for $100, the seller receives the $100, 
not for so much dirt, but really for the constituents 
contained in it. The purchaser believes that, with the 



ARTIFICIAL LOSSES OF FERTILITY 15 

conditions surrounding them, he can convert them 
into products which he can sell and from which rea- 
lize a profit. If in selling these amounts of the con- 
stituents in the form of land, a lower price per acre 
is received, it is because the natural conditions which 
surround them, and which influence their utility, are 
less favorable, and a greater proportionate effort and 
expense are necessary to secure them in the form of 
salable products. The difference in 'the price of land 
is not always due to the content of the constituents, 
but often to the conditions surrounding them. In 
many cases, the soil may serve simply as a medium in 
which plants can grow, and the content of the fertility 
elements is of minor importance. Such would be the 
case in the growing of market -garden crops near 
large cities, the location near the consumer being of 
greater importance, in the case of perishable crops of 
this sort, than the chemical character of the soil. In 
the large majority of cases, however, the natural fer- 
tility fairly measures the market price. At the price 
per acre, and for the quantity of constituents here 
assumed, the buyer would pay at the rate of 1% cents 
per pound for the nitrogen, and % cent per pound 
each for the phosphoric acid and potash, and it now 
constitutes his capital stock. 

A Comparison of the Prices Received for the Fertility 
Elements in Different Crops 

A comparison of thi; prices paid for the constitu- 
ents in land, with the prices received for the same 



16 FERTILIZERS 

constituents when contained in the different crops 
(disregarding for the moment the value of the "con- 
dition" of soil), will make clearer this matter of 
rational sale of constituents, which represents a re- 
duction of our capital stock of fertility. For exam- 
ple, if wheat is raised, which contains 1.89 per cent 
of nitrogen, .93 per cent of phosphoric acid and ,64 
per cent of potash — or in round numbers, 38 pounds 
of nitrogen, 19 of phosphoric acid and 13 of potash 
per ton — and is sold for 60 cents per bushel, or $20 
per ton, the nitrogen sells in this form for 41 cents 
per pound, and the phosphoric acid and potash for 
14 cents each per pound. That is, the 60 cents per 
bushel, or the 41 cents per pound, received for the 
nitrogen, and 14 cents for the potash and phosphoric 
acid, represent what has been received per pound for 
the capital stock of these elements, which at $100 
per acre were purchased at the prices previously men- 
tioned. The labor in raising the crop, the expense of 
harvesting and putting it upon the market, and the 
profit, must come out of the difference between what 
is paid and what is received. Naturally, as the ratio 
between the constituents contained in the products 
sold and the price received is increased, the rate o\ 
income per unit of exhaustion is increased, though 
in many cases the increased cost of the labor neces- 
sary is in proportion to the increased price received. 
This may be illustrated by a comparison on the fer- 
tility basis of the sale of wheat and milk. If milk, 
which contains on the average 12 pounds of nitrogen, 
4% pounds of phosphoric acid and 3% pounds of 



FERTILITY CONTENT OF FARM CROPS 17 

potash per ton, is sold for $1.50 per hundred pounds, 
the nitrogen is sold for $2 per pound, and the phos- 
phoric acid and potash for, approximately, 70 cents 
per pound. In the sale of milk at this price, the rate 
of income per unit of exhaustion is increased nearly 
five times over that of the wheat, though, because it 
is in one sense a manufactured product, the cost of 
labor per unit of plant -food contained is largely in- 
creased. Again, if cream is sold, the prices received 
for the constituents are still further increased, while 
if the milk is made into butter, and that alone is 
sold, the prices received measure the expenses and 
profit, and the capital stock of fertility is not mate- 
rially reduced, though it is in another form and in 
another place. 

Fertility Content of Cereals and Vegetables 

The losses of the constituents in the sale of ce- 
reals and grasses, corn, oats, wheat and hay, are, too, 
relatively greater than in the sale of vegetables and 
fruits, as lettuce, celery, potatoes, tomatoes, sugar 
beets, apples, berries and kindred crops, though in 
the case of the latter, a higher degree of fertility is 
necessary in order to produce maximum crops, and 
the cost of production is again proportionately greater. 
These facts strongly emphasize the necessity of a care- 
ful study of the relation of farm practice to the arti- 
ficial losses of fertility. 

The artificial loss of fertility that may be incurred 
by the sale of crops is largely measured by the knowl- 



18 FERTILIZERS 

edge of the producer coneerniug the relation between 
the price received for the crop and the fertility con- 
tained in it, and thus removed when sold, and by his 
intelligence in adjusting his methods so is to reduce 
to a minimum the actual loss. 

Irrational Farm Practice 

There are methods of practice which are entirely 
irrational, and contribute to the real losses of fertility. 
Farming is unprofitable, not altogether because the 
land is exhausted, but because only those crops are 
grown which possess a high fertility value, and which 
have a low market price, and thus the prices received 
for the constituents in the crop are actually less than 
they cost in land and in labor ; and these methods of 
practice are not confined to farmers whose lands of 
inexhaustible fertility have been given them by a 
generous government, but are followed by farmers 
who annually purchase commercial fertilizers to supply 
the losses of fertility thus sustained. 

Where the conditions are such as to make it im- 
practicable to grow and sell crops, as such, of a low 
fertility value, the producer should endeavor to sell 
the manufactured rather than raw materials, — that 
is, to so use his crude products as to lower the quan- 
tity of the constituents contained in those sold, which 
explains, in part, the greater success in the long run 
of a mixed husbandry, rather than single -crop 
farming. 

The artificial losses of our national capital stock of 



IRRATIONAL FARM PRACTICE 19 

fertility are, however, not absolute, if the products 
are consumed in our own country, as more or less of 
the constituents contained in the crude [products sold 
find their way back to the farm, either in the by- 
products of the mills, in sewage, in the manure from 
cities, or in various vegetable or animal wastes ; but 
when they are exported the loss is absolute, and the 
amounts so disposed of are in some degree a measure 
of the rate of loss of the capital stock of fertility in 
our lands, though to these must be added the losses 
due to the improper use of manure and other waste 
materials. 

Losses in Manures 

It is natural to infer that proper losses of fertility 
are confined to the removal of the constituents in the 
sale of farm products, and that those contained in the 
materials not sold and in the feeds used upon the farm, 
are again returned to the land. Theoretically this is 
correct, but the losses that do occur, particularly in 
the handling of manures, should not be overlooked. 
While it is impossible to even roughly estimate the 
waste or loss of fertility due to the improper making 
or handling of manures, some idea may be obtained 
when the enormous amounts produced and the sources 
of possible loss are considered. 

If this enormous mass of waste material were 
properly used, it would go a great way toward increas- 
ing the present and immediate fertility of our soils, or 
in retarding the time of exhaustion, and it is quite 
pertinent to inquire if it is properly used. It has 



20 FERTILIZERS 

been demonstrated by experiments* that 50 per cent 
of the total constituents in farm manures is liable to 
be lost by ill -regulated fermentation and by leaching ; 
and further, careful observations and experiments 
show that the conditions in the majority of barnyards 
are such as to encourage the maximum loss by these 
means. It is morally certain that a large percentage 
of the constituents contained in them are lost ; they 
never reach the right place on the farm. 

It is estimated that if but one -tenth of the present 
waste could be avoided, — and a very large part of it is 
practically avoidable, and at a very slight expense, — 
the total amount of constituents that may thus be 
saved for further use would be more than equivalent 
to the amounts now purchased in the form of com- 
mercial fertilizers. This estimate is certainly conser- 
vative, and clearly demonstrates the serious drain 
upon our resources of fertility elements, due to the 
lack of care in the handling of farm manures. 

The conditions, as here pointed out, not only sug- 
gest the need of imported plant-food, but that there 
are opportunities for reducing this need by careful 
saving and use of the constituents that are subject to 
waste. 



'Bulletin 56, Cornell Univ. Agr. Ex. Sta., Ithaca, N. Y. 



CHAPTER II 

THE FUNCTION OF MANURES AND FERTILIZERS, AND 
THE NEED OF ARTIFICIAL FERTILIZERS 

While in a broad sense, a manure or fertilizer may 
be regarded as anything that will increase the yield of 
a crop if added to the land, the chief function of 
manures is to furnish nitrogen, phosphoric acid and 
potash. 

THE ESSENTIAL ELEMENTS OP FERTILIZERS 

These are called the "essential manurial elements," 
or "constituents," to distinguish them from the others 
that are needed by plants, because these three are con- 
tained in the crops removed in greater amounts than 
the others, and because they exist in the soil in much 
smaller amounts than the others. For example, culti- 
vable soils seldom contain too little iron or sulfur, or 
magnesium. These elements usually exist in quantities 
more than sufficient to supply all the needs of the 
plant for them, and, because they are required in such 
exceedingly small amounts, the soils are seldom ex- 
hausted of them. In addition to this property of 
supplying essential manurial constituents, many sub- 
stances useful as manures possess, however, a secondary 
function : they serve to indirectly increase the crop, 

(21) 



22 FERTILIZERS 

but do not add directly to the potential fertility of 
soils. 

NATURAL MANURES AND ARTIFICIAL FERTILIZERS 

Farmyard manure, and many other natural pro- 
ducts, possess this second function in a marked de- 
gree, and the indirect manurial value of these is due 
largely to the good effect that the substances asso- 
ciated with the nitrogen, phosphoric acid and potash 
in them exert in increasing the crop. This good 
effect is observed in two directions. First, the vege- 
table matter contained in the natural manure improves 
the physical character of soils — those that are clayey 
and compact, by making them more open and porous, 
separating the particles, so that the water and air can 
penetrate more freely, and thus act directly upon the 
dormant or insoluble constituents that are contained 
in it ; and those that are light and sandy, by filling 
up the open spaces, thus making them more compact. 
In the second place, the addition of vegetable matter 
to soils, even though it contains no essential consti- 
tuents, improves it by enabling it to more readily and 
completely absorb and retain not only the water, but 
also the soluble essential constituents that may be 
added. The chief distinction between what are 
known as manures and what are known as ferti- 
lizers, is the difference in respect to this secondary 
function. The manure possesses the two functions, 
the one to supply the essential constituents, and the 
other to assist plant growth by aiding in the improve- 
ment of those ah-eady contained in the soil, and this 



THE FUNCTIONS OF MANURES 23 

latter function it exerts in a marked degree; while the 
fertilizer, as a rule, possesses but one, namely, that 
of furnishing plant -food. The indirect effect of the 
materials associated with the constituents in artificial 
fertilizers is seldom very useful, and sometimes may 
be harmful. 

DIRECT AND INDIRECT EFFECT OF MANURES 

It is obvious, therefore, that any substance which 
contains nitrogen, phosphoric acid or potash may 
serve as a direct manure, and any substance which 
contains no plant-food, but which possesses the power 
of improving the physical character of soils, may also 
serve as a manure, though the one effect is quite dis- 
tinct from the other. The first adds to the soil the 
essential constituents; the other helps to make the con- 
stituents already in the soil serve as food to the plant. 

The use of the one will tend to increase both the 
potential and practical fertility in the soil, while by 
the use of the other, the active fertility is increased 
as the potential fertility is decreased. That is, when 
actual plant -food is added in the form of nitrogen, 
phosphoric acid or potash, and crops are removed, the 
exhaustion of the soil is in proportion to the amounts 
of these removed over and above the amounts which 
have been added. Whereas, in the other case, when 
no plant -food is added, the exhaustion is measured by 
the amount of the constituents removed. It is clear, 
therefore, that the addition of only indirect manures 
has a tendency to rapidly reduce the fertility of soils 



24 FERTILIZERS 

of low natural strength, or those that do not possess 
large stores of food constituents, whereas, on soils 
that are rich in the fertility elements, the indirect 
manuring may result in an increased yield for a long 
period, though ultimately the soil will become ex- 
hausted — if not completely, to such a degree as to 
render further cropping by this method unprofitable. 

UNAVAILABLE AND AVAILABLE PLANT -FOOD 

While, as already stated, any material containing 
either one or all of the three essential constituents, 
nitrogen, phosphoric acid or potash, may serve as a 
direct manure in the sense that it increases the poten- 
tial fertility of any soil, the value of the addition of 
such materials will depend not so much on the 
amount, as upon the power that the plant may 
possess of acquiring it — and it is here that the dif- 
ference between manures from natural sources and 
those from artificial sources is again quite manifest. 
That is, the fertility constituents in natural manures 
are in large part combined with others in the form of 
vegetable matter, and with the exception of potash, 
they are, when in this form, largely insoluble, and, 
therefore, cannot be used by the plants until after 
decay begins. Whereas, in artificial manures, the 
constituents may be not only soluble, but may be in 
a form in which the plants can take them up im- 
mediately. In the first case, the plant -food is said 
to be unavailable, and in the second, it is said to be 
available. 



AVAILABLE PLANT-FOOD 25 

Nitrogen, one of the chief constituents of manures, 
for example, exists in three distinct forms : (1) the 
organic form, in animal or vegetable matter, which 
must first decay before it can serve as plant -food. (2) 
As the decay goes on ammonia is formed, and then 
(3) from the ammonia the nitrate is formed, which is 
the form in which plants take up the largest proportion 
of their nitrogen. Inasmuch as products exist which 
contain nitrogen in these three distinct forms, it is 
possible by their use to largely control the feeding of 
the plant in respect to this element, while in the case 
of natural manures, the feeding of the plant with 
nitrogen depends upon conditions which cause its 
change from the organic into the other forms. 
As these conditions are variable, the problem of 
the economical feeding of plants with nitrogen, other 
things being equal, becomes a more difficult matter 
with the natural than with the artificial manures. 

Phosphoric acid also exists in different forms, the 
form measuring to a large degree its availability : the 
organic, in which the availability depends upon the 
rapidity of decay ; and the soluble and immediately 
available form, — that is, the form that distributes 
everywhere, and which the plant can absorb immedi- 
ately it comes in contact with the roots. Commercial 
products exist which contain the phosphoric acid in 
these distinct forms. The user is therefore enabled 
to supply this constituent in such form as may best 
suit his crop and soil conditions. 

In the case of potash, distinct forms, as muriate, 
sulfate and carbonate, also exist, though in the case 



26 FERTILIZERS 

of potash, the form iu which it is combined exerts 
less influence upon the availability of the element to 
the plant than is the case with nitrogen and phos- 
phoric acid. All of these forms are soluble, and can 
be readily absorbed. 

DANGER OF LOSS FROM THE USE OF SOLUBLE 
PLANT -FOOD 

The fact that the artificial fertilizer -products con- 
tain the constituents in such forms and combinations 
as to enable them to feed the plant immediately, also 
presents some disadvantages from the standpoint of 
economical use. This is particularly true in the case 
of nitrogen, for nitrogen, when applied in the form 
of nitrate, in which form it is taken up by the plant, 
does not combine to make insoluble compounds, but 
remains freely soluble. A great waste, therefore, may 
ensue from leaching into the lower layers of the soil 
and beyond the roots of plants, or into the drains, 
and the plant -food be carried away, unless care is 
exercised both as to the amount and the method of 
application. With soluble phosphates, the danger of 
loss is much less than with nitrogen. If these are ap- 
plied in too large quantities to meet the needs of the 
plants, or under improper conditions, their tendency 
is not to remain soluble, but to revert to their 
original and insoluble form. The main fact, however, 
is that in artificial fertilizers we may have the con- 
stituents in distinct and separate forms, which permits 
the feeding of the plant, rather than the feeding of 



CHEMICAL FEBTILIZUSS ARE EFFICIENT 27 

the soil ; and this is usually, and must necessarily 
be, the case when natural manure products serve as 
the entire source of the added fertility. 

THE USEFULNESS OF A FERTILIZER CONSTITUENT DOES 
NOT DEPEND UPON ITS ORIGINAL SOURCE 

It should be remembered, too, that artificial ma- 
nures or fertilizers supply plant -food just as well as 
other and more common products. The fact that 
the food exists in substances other than those which 
are familiar to the farmer, is no evidence that it may 
not be quite as good, or even better, than when con- 
tained in his home-made products. It is not the out- 
ward appearance of a substance, but the kind and 
form of the elements contained in it, that measures 
its value as a fertilizer. 

For example, the nitrogen that may be applied in 
the form of a commercial fertilizer exerts no different 
function in the plant than that which may be acquired 
from the original soil, or from materials that have 
recently been obtained from that soil, and again 
returned as yard manure. The same is true of phos- 
phoric acid and potash. In their concentrated, artificial 
forms, they serve to feed the plants in exactly the 
same way, and exert the same function in them, as 
those contained in the soils themselves, or that may be 
contained in wood ashes, or materials more familiar, 
or of more common occurrence. The form in which 
they exist when applied does not necessarily imply 
that they are stimulants rather than food, though fre- 



28 FERTILIZERS 

quently, because of their form, the plants are able to 
absorb them more readily, and thus by their rapidly 
increased growth, encourage a belief that an undue 
stimulating effect accompanies their use. The famous 
experiments of Lawes & Gilbert, at Rothamsted, 
England, teach this one thing very emphatically; viz., 
the efficiency of chemical fertilizers as compared with 
yard manures.* 

USE OF FERTILIZERS 

While manures in the ordinary sense, and even 
materials which are now included under the head of 
artificial manures, such as ground bone and wood 
ashes, have been used for a very long time, the use 
of artificial products in a true sense is of compara- 
tively recent origin. The first use of genuine artificial 
fertilizers dates from the publication of Baron von 
Liebig's book, "Organic Chemistry in Its Application 
to Agriculture and Physiology," in 1840 ; yet for a 
long time after this date the increase in their use was 
very gradual. The verj^ excellent, and at that time 
surprising, results which were obtained from the 
application of Peruvian guano, one of the first 
products to receive attention, manifestly increased the 
interest in the subject, also. These good results were 
observed more particularly on the continent of 
Europe, where the lands had been under cultivation 
for a long time. The use in America, previous to 
1860, was quite insignificant. Since the work of 



* Rothamsted Memoirs, Volumes l.-vl. 



TEE USE OF FERTILIZERS 29 

Liebig, a very great amount of study has been given 
to the subject, both in reference to the essential char- 
acter of the various materials, and their influence 
upon the production of plants. Perhaps no other 
single subject relating to agricultural science has been 
studied more fully than the question of the use of 
artificial manures ; and these studies have resulted, 
not only in the discovery of new materials, but in 
their better preparation for use as plant -food, which 
greatly increased their effective use. There is no 
question connected with agriculture which is of greater 
direct and practical importance, particularly in those 
countries which have been depleted of their active 
fertility by the means mentioned, or in which the 
conditions are as previously outlined, than definite 
knowledge of the true principles which govern in the 
profitable use of commercial fertilizers. Yet, not- 
withstanding all the good results thus obtained, and 
their great practical importance to agriculture, much 
still remains to be done, particularly in the establish- 
ment of fundamental principles. 

While it is desirable that in a work of this kind, 
scientific discussions should be avoided as far as pos- 
sible, and the subject made as plain as is practicable 
to those using fertilizers, it is necessary to their 
right use that those who apply them to their land 
should have a very clear conception of the underlying 
principles, so far as they are known, in order that 
they may intelligently increase their production, and 
thus reap a profit. Definite knowledge is an im- 
portant factor in determing their profitable use. 



30 FERTILIZERS 

THE NEED OF ARTIB^ICIAL FERTILIZERS 

The considerations in the previous chapter 
explained in part, and in a broad, general way, the 
necessity for the use of commercial fertilizers. The 
conditions of farming in this countrj' have greatly 
changed in the past thirty years, and these changes 
have, perhaps, a still more important bearing in show- 
ing the need of imported fertility than the conditions 
already discussed. The first direction in which 
important changes have taken place is in the in- 
creased cost of farm labor and in the relatively low 
prices now received for the staple crops, the cereal 
grains, cotton and tobacco. 

The Cost of Production per Unit of Income 
is Increased 

The cost of labor is increased because proportion- 
ately higher wages are now paid, and because the 
labor now obtainable is on the whole less efficient, 
being performed more largely by those untrained 
for their work, rather than by the owner and his 
sons ; and this increased cost of labor makes the cost 
of growing the staple crops much greater in propor- 
tion to their market value than was formerly the 
case, though there are, of course, exceptions. 

For example, harvest wages throughout the east- 
ern part of the country, at any rate, were in the 
sixties regulated somewhat })y the price of wheat. 
When wheat was $3 per bushel in the eastern states, 



TEK NEED OF FERTTLIZEBS 31 

the daily wage was $3. Now the daily wage in the 
east ranges from $2 to $2.50 per day, while the price 
of wheat does not often exceeed $1 per bushel, and 
the price received is frequently much lower than 
this. The wages for other kinds of farm work are 
proportionately the same in reference to present / 
prices of products. This condition, when considered 
in connection with the important fact that the total 
cost of crop per acre is practically the same, whether 
the yield is high or low, exerts a decided influence 
in determining profits, particularly on land of 
medium fertility. The cost of preparing the land for 
the seed, the cost of seed, and the seeding and 
harvesting, are the same for a crop of wheat, whether 
the yield is 10 or 30 bushels per acre ; but this cost 
will not permit a profit from the 10 -bushel yield, 
because the cost per bushel is too largely increased. 
The same considerations hold true for a number of 
other crops. Small yields of these relatively low- 
priced crops cannot be profitably produced with the 
present high price of labor ; and it has been shown, 
furthermore, that land which is not in a high state 
of fertility will not produce large yields. 

Many soils, especially those in the eastern and 
southern sections of our country, which were not 
originally very fertile, and which have been cropped 
for a long time, show abundant evidence of the need 
of fertility from sources outside of the farm, in order 
that maximum crops may be produced. The aim should 
be, therefore, to make the conditions of soil better, and, 
if possible, so perfect as to guarantee against any 



32 FERTILIZERS 

lack of food during the growing period, and thus 
make the conditions of climate and season, rather than 
the soil, the measure of the crop. That is, as far as 
practicable, the yield that it is possible to obtain in a 
given locality should be the aim of the farmers in that 
locality. In order to make the conditions of soil per- 
fect in this respect, the fertility elements must be 
added, though indirect manuring, iu the form of better 
cultivation and better use of the waste products of the 
farm, are also to be encouraged. 

A Oreater Demand for Special Crops 

In the second place, the changed conditions of 
farming are shown in the constantly increasing demand 
for market - garden products and fruits. Not many 
j'ears ago, the staple crops already described were prac- 
tically the only ones raised and sold from the farm. 
The growing of vegetables and fruits was limited. They 
were regarded as luxuries, and the area given to them 
was, on most farms, only sufficient to meet the needs 
of the home. These were not regarded as crops in the 
same light as the others, and were seldom the source 
of direct income. At the present time, vegetables and 
fruits are regarded as necessities in every home, and 
their use is not confined to the season in which they 
can be provided in the immediate vicinity of the cities 
or towns where they are used ; they are drawn from 
points far distant, and the demand is such as to re- 
quire the use of wide areas in order to supply the 
needs. The growing of market- garden crops and fruits 



FARM MANURES ARE INADEQUATE 33 

is now the basis of specific agricultural industries 
which have assumed large proportions. 

Much progress has been made, too, in the develop- 
ment of methods of practice in these lines of farming, 
and the experience gathered has shown that even our 
most fertile soils in their natural conditions contain 
too little active food to insure maximum yields of crops 
of the best quality ; in these lines of farming, too, 
earliness and edible quality of products, which are 
influenced by the food supply, are important factors in 
determining the profits to be derived. The areas now 
necessarily devoted to these crops are so great that 
soils of a high natural fertility, even if natural fertility 
alone could be depended upon, are too limited to meet 
the demand and enable a profit, especially in the vicin- 
ity of good markets ; in other respects a good location, 
because permitting of cheap distribution, is an impor- 
tant factor. 

Farm Manures are Inadequate 

Farm manures might meet the needs for the staple 
crops, as they are well adapted in many respects for 
the purpose, but, under present systems of manage- 
ment, the amount is not sufficient to meet the annual 
losses from the sale of crops, much less to provide an 
increase, and the only other source is an artificial 
supply, or commercial fertilizers. For the special 
crops already described, the natural manures of both 
farm and city are not only not sufficient, but, because 
of their character and composition, are not well adapted 
c 



34 FERTILIZEUS 

to economically meet the entire demands of the plants. 
In the first place, they are bulky, and thus expensive 
to handle. In the second place, the fertility elements 
contained in them are not in good proportion ; they 
are, as a rule, poor in the mineral elements and rich in 
nitrogen, and their use in sufficient amounts to meet 
the needs of the plant for the mineral elements results 
in a waste of the nitrogen. Third, the constituents 
contained in them are not in sufficiently active forms 
to provide for a rapid and continuous growth without 
an excessive application, which frequently results in a 
serious waste not only of the nitrogen, as already indi- 
<;ated, but, in the case of manj^ crops, an abnormal 
growth of vine or stalks, which may seriously injure 
the marketable quality of the crops. For many crops, 
economical production requires that the natural ma- 
nures should be supplemented by artificial supplies, by 
means of which the form and amount of the individual 
constituent can be regulated to meet the needs of the 
various plants. 

The Orowinfj Importance of Fruit-growing 

In fruit -culture, an industry of growing importance, 
il has been found that soils in their natural condition, 
while they may be well adapted in other respects — that 
is, possess a suitable physical character for the growth 
of this class of crops — contain insufficient amounts of 
the mineral constituents which are required in order 
that continuous and large crops of perfect fruit may 
be secured. To supply this deficiency from vard ma- 



THE RIGHT USE OF FERTILIZERS 35 

nure would cause in many cases an over -supply of vege- 
table matter containing nitrogen, which for these crops 
is frequently followed by disastrous results, not only 
causing an abnormal growth of leaf and wood, but 
inducing it at such periods of the year as to materially 
interfere with the proper ripening of both the wood 
and the fruit. By the use of artificial fertilizers, these 
difficulties may be largely overcome. 

WILL IT PAY TO USE FERTILIZERS ! 

It must be confessed that to give a definite and 
positive answer to this question, with our present state 
of knowledge, is a difficult matter, if not well-nigh 
impossible, because of the very large number of vary- 
ing conditions that are involved. 

Usually such a question cannot be answered in a 
rational way without first securing definite information 
concerning the conditions under which they are to be 
applied, as, for instance, the character of soil, whether 
a sand, clay or loam; situation in reference to mois- 
ture, whether too dry or too wet; the kind of subsoil, 
whether a loose, open sand or gravel, a medium clay, 
or a tight, impervious hard-pan; the character of the 
previous treatment and cropping, whether the land has 
been manured or fertilized, whether good cultivation 
has been practiced, whether leguminous crops have 
been grown to any extent, whether the produce raised 
has been sold, or fed on the land; whether the object 
of the growth has been for immature produce and for 
early market, and artificial growth demanded, or 



36 FERTILIZERS 

whether for maturity, when the natural tendency has 
simply been assisted and the development normal in 
all directions. 

If these questions are answered truthfully and in 
detail, a scheme of fertilization may be adopted that 
will enable the farmer to secure the greatest returns 
for the plant -food applied. 

That the returns from the use of fertilizers are 
frequently unprofitable, is not always the fault of the 
fertilizer, and this point may be illustrated by 
the following typical case: One farmer applies 
plant -food, his crop is doubled or trebled, and a rea- 
sonable profit is secured. Another farmer applies the 
same amount and kind of fertilizer under similar 
natural conditions of soil, and he receives no benefit. 
The same climatic conditions surrounded the crops of 
both, the sun that warmed the soil and furnished the 
energy necessary for the production of the largely 
increased crop, is the same sun that shone upon the 
small crop; the air that furnished a large proportion 
of the food for the one is the same air that surrounded 
the other; the rains that moistened and assisted in 
the solution and circulation of plant -food for the one 
were the same for the other. Why, then, the difference 
in results? In one case the natural agencies, sun, air 
and water, were assisted and enabled to do their 
maximum work, while in the other, they were pre- 
vented from exercising their full influence. Physical 
conditions of soil were imperfect, due to careless plow- 
ing, seeding, cultivation and cropping. 

In other words, the profit from the use of plant- 



THE WASTEFUL USE OF FERTILIZERS 37 

food is measured to a large degree by the perfection of 
soil conditions, which are entirely within the power 
of the farmer to control. The production possible 
from a definite amount of plant -food can be secured 
only when the conditions are such as to permit its 
proper solution, distribution and retention by the soil. 

The fact that fertilizers may now be easily secured, 
and the ease of application, have encouraged a care- 
less use, rather than a thoughtful expenditure, of an 
equivalent amount of money or energy in the proper 
preparation of the soil. Of course, it does not follow 
that no returns are secured from plant -food applied 
under unfavorable conditions, though full returns 
cannot be secured under such circumstances. Good 
plant -food is wasted, and the profit possible to be 
derived is largely reduced. 

Again, because farming, in its strict sense, is the 
conversion of three essential elements into salable 
products, the time to apply plant -food must be 
governed largely by its cost and the kind of crop 
upon which it is applied. 



CHAPTER III 

NITROGENOUS FERTILIZERS 

Nitrogen is the most expensive constituent of fer- 
tilizers, and, all things considered, it is one of the 
most useful. Nitrogen exists in nature as a compo- 
nent of the air, and though quite as necessary to 
vegetation as carbon or oxygen, — which also exist in 
the atmosphere, and which are readily acquired by 
all plants, — all plants do not have the power of acquir- 
ing nitrogen from this source. This power seems to 
be limited to a class of plants called Leguminosge, to 
which belong the various clovers, peas, beans, vetches, 
and a number of others. The important farm crops 
belonging to the other botanical groups of plants 
obtain their nitrogen largely, if not altogether, from 
the soil. 

Vegetable or animal matter containing nitrogen 
may serve as a source of nitrogen to plants, though 
it cannot feed them with this element to an}' extent 
until it decays or rots. In order to obtain a clear 
conception of the use of nitrogen as a fertilizer, we 
should understand the need of plants for it, what is 
meant by form of nitrogen, and the sources from 
which the various forms may be derived, as well as 
the relative agricultural or crop -producing value of 
the nitrogen in existing commercial forms. 

(38) 



rORMS OF NiTBOOJSIf 39 

WHAT IS MEANT BY FORM OF NITROGEN? 

Strictly speaking, form of nitrogen has reference 
to its combination or association with other chemical 
elements, though sometimes the term form is used 
to indicate rate of solubility, which also measures 
to some degree availability, since it happens that 
soluble forms of nitrogen are really more available 
than the insoluble forms, though neither the soluble 
nor insoluble forms show the same rate of availabil- 
ity; that is, a pound of soluble nitrogen is not equally 
available from whatever source derived, and a pound 
of insoluble from one source may be much more avail- 
able than a pound from another. The form in which 
nitrogen exists in vegetable and animal matter is 
called the "organic form," because it is associated 
with other constituents, as carbon, hydrogen and 
oxygen, which are necessary to make the substances 
that constitute animal or vegetable matter, as we see 
them. The term "organic," as applied to nitrogen, 
covers a whole series of substances, and does not 
indicate a uniformity, either in content or quality of 
the nitrogen, as is the case with distinct chemical 
compounds; hence, associated with the knowledge of 
form of nitrogen, when it exists in organic products, 
must be a knowledge of whether the material contains 
a very considerable amount of nitrogen, and whether 
it is likely to be readily changed, and thus become 
available as food for plants. 

Any nitrogenous vegetable or animal matter may 
serve as a fertilizer, though organic nitrogen in com- 



40 FERTILIZERS 

mercial fertilizers is usually obtained from products 
relatively rich in this constituent, and it is only these 
that can be used to advantage in making what are 
known as "high-grade fertilizers." The leading ani- 
mal substances of this class are now mentioned. 

DRIED BLOOD 

One of the chief products from which organic 
nitrogen is derived for commercial fertilizers is dried 
blood. It is one of the most important, because it is 
one of the most concentrated, one of the richest in 
nitrogen of the organic nitrogenous fertilizing ma- 
terials, and it is one of the best, since its physical 
character is such as to permit of its very rapid decay 
in the soil during the growing season. This tendency 
to rapid decay is plainly apparent, when we remember 
that blood as it exists in the animal is in a fluid 
form, and naturally any material which is sufficiently 
finely divided to permit of its ready flow, and is not 
associated with any hard or fibrous material, possesses 
characteristics which enable a rapid breaking down 
when subjected to the proper temperature and mois- 
ture, conditions which promote decay. 

Dried blood for fertilizing purposes is chiefly ob- 
tained from the large slaughtering establishments, and 
the markets recognize two distinct kinds; namely, that 
which is red and that wliich is black. The red dried 
blood results from the careful drying of the fresh 
blood with hot water, at which temperature it does 
not char, nor become injured in quality. When dried 



HIGHGBADE NITBOOENOUS MATERIALS 41 

at a higher temperature, and by other methods, it is 
darker in color, and has a leathery character, is less 
useful in the arts, and is slower to decay. Red blood, 
which commands the highest price, is reasonably uni- 
form in composition. It contains from 13 to 14 per 
cent of nitrogen, and but traces of phosphoric acid — 
it is always classified as "high-grade." The black dried 
blood is of a lower grade, and may range in content 
of nitrogen from 6 to 12 per cent ; it also contains 
considerable phosphoric acid, frequently as high as 4 
per cent. Usually the lower the content of nitrogen, the 
higher the content of phosphoric acid ; the latter is 
contained in the impurities (other substances, largely 
bone) with which it is contaminated. The lower grade 
blood is very generally used in the manufacture of 
fertilizers, since it is really the only good use to which 
it may be put; the high-grade is useful for other 
commercial purposes. 



DRIED MEAT OR MEAL, AZOTIN, AMMONITE, OR 
ANIMAL MATTER 

Dried meat or meal, azotin, ammonite, or animal 
matter, are terms applied to practically the same pro- 
duct, though produced in a different way. This ma- 
terial is another source of high-grade organic nitrogen. 
It is rich in the constituent element, and also decays 
rapidly in the soil. When relatively pure, it contains 
as high as 13 or 14 per cent of nitrogen, and thus in 
this respect compares very favorably with blood. The 
largest supply comes from rendering establishments, 



42 FERTILIZERS 

where the different portions of dead animals are util- 
ized. These are subjected to treatment, usually dried 
and extracted with steam, for the purpose of securing 
the fat, though formerly, and even now, a large por- 
tion of this product is obtained from the beef extract 
factories. 

HOOF MEAL. 

Hoof meal is a reasonably uniform product, rich 
in nitrogen. It averages as high as 12 per cent, and 
in reference to availability has heretofore been classed 
with low-grade products. In recent cultural experi- 
ments, however, the results indicate that it is much 
more valuable as a source of nitrogen than leather, 
wool or hair. Commercially, it ranks with the high- 
grade products. 

DRIED AND GROUND FISH, OR FISH GUANO 

This product is obtained from two sources: first, 
from the offal, largely bones and skins, of fish packing 
or canning houses; and second, from the fish pomace 
resulting from extraction of the oil from the men- 
haden. The latter product is richer in nitrogen and 
is more uniform in character than the wastes from 
the packing houses. Dried ground fish from this 
source contains from 7 to 8 per cent of nitrogen, and 
from 6 to 8 per cent of phosphoric acid. The former, 
owing to the varying proportions of bone, skin and 
flesh contained in it, varies widely in its content of 



TANKAGE 43 

nitrogen. Fish, besides affording a considerable supply 
of nitrogen, is also regarded as a good source of this 
element, ranking in availability well up to blood and 
tankage, and is largely used in the northern coast 
states, where the supply is reasonably abundant. 

KING CRAB 

King crab is found in considerable quantities 
along the Atlantic coast, and is not only used directly 
as a fertilizer, but is also dried and ground and intro- 
duced into commercial mixtures. It is a highly nitrog- 
enous product, containing in the dry state an average 
of 10 per cent, with traces only of phosphoric acid. 
It also possesses a high rate of availability, though 
information on this point is derived from the practi(3al 
experience of farmers, rather than from actual scien- 
tific test. 

TANKAGE 

Tankage is a highly nitrogenous product, and con- 
sists chiefly of the dried animal wastes from the large 
abattoirs and slaughtering establishments. It is va- 
riable in its composition, since it includes the otherwise 
unusable parts of the carcass, as bone, tendons, flesh, 
hair, etc. The portions of this from the different 
animals not only vary in their composition, but they 
are used in varying proportions, which naturally re- 
sults in an extremely variable product. What is known 
as "concentrated tankage," which is obtained by evap- 



44 FERTILIZERS 

orating the fluids which contain certain extractive 
animal matter, is the richest in nitrogen, and is more 
uniform in character than the others ; and because of 
its fineness of division and physical character, the 
nitrogen contained in it is also more active than in 
the other forms. Two distinct kinds of tankage can, 
therefore, be obtained; first, concentrated tankage, 
which is the richer in nitrogen, ranging from 10 to 12 
per cent, and which contains very little phosphoric 
acid; and second, crushed tankage, which is of several 
grades, ranging from 4 to 9 per cent nitrogen, and 
from 3 to 12 per cent of phosphoric acid. Products 
are sometimes sold as tankage, which contain much 
more than the maximum of phosphoric acid and less 
than the minimum of nitrogen here given, in which 
case they are to be classed with bone, rather than with 
tankage. Tankage varies so much, both in its content 
of phosphoric acid and nitrogen, that in the trade it is 
always sold on the basis of its composition. The per- 
centage of nitrogen and phosphoric acid is distinctly 
stated, and because it contains very considerable 
amounts of phosphoric acid, its commercial value is 
not wholly based on its content of nitrogen, as is the 
case with dried blood, dried meat, and concentrated 
tankage. 

GARBAGE TANKAGE 

Garbage tankage is a name given to a product now 
obtained by the drying, and sometimes partial charring, 
of the garbage of cities. It usually contains variable 



LEATHER, WOOL AND HAIR 45 

percentages of all of the constituents, though chiefly- 
valuable for the nitrogen, and as yet cannot be classed 
among the standard fertilizer supplies, because of its 
variability, and because the usefulness of the con- 
stituents have not yet been determined. 

LOW-GRADE NITROGENOUS PRODUCTS 

Other products which contain a high content of 
nitrogen are frequently used. These, because of their 
low rate of availability, constitute a separate and dis- 
tinct class. For example, horn meal, or ground horn, 
is reasonably uniform in its composition or content of 
nitrogen. It contains as high as 10 or 12 per cent of 
nitrogen, but it is slow to decay when used in its 
natural state, and, therefore, is not regarded as an eco- 
nomical source of this element, unless it can be ob- 
tained at a low price. 

Leather meal. — Leather meal is another product 
which is rich in nitrogen, but which is so slow to decay 
that its use in the natural state is not recommended. 
One object in making leather is to render it resistant 
to the conditions which promote decay, and ground 
leather may remain for years in the soil in an un- 
changed condition. 

^Yool and hair ivaste. — Wool waste and hair waste 
are also products which exist in considerable quanti- 
ties, and while variable in composition, are frequently 
rich in nitrogen, but they are classed with leather 
because of their slow activity. Their mechanical form, 
coarse and bulky, makes it impossible to use them to 



46 FERTILIZERS 

advantage in the manufacture of fertilizers without 
previous treatment. The use of these materials, un- 
treated, can only be regarded as desirable when they 
mjiy be obtained at a very low cost. When dissolved 
with acid, or treated in such a way as to render them 
more immediately available, they may be used to ad- 
vantage, though the cost of such treatment is usually 
so great as to make it impossible to thus improve their 
form and still be able to compete commercially with 
the other nitrogenous products. 

VEGETABLE NITROGENOUS PRODUCTS 

Cotton- seed meal is one of the best of the vegetable 
nitrogenous fertilizing materials. It is reasonably con- 
centrated, and decays rapidly. Tests which have been 
made show that it ranks with blood in the availability 
of its nitrogen. Properly prepared, that is, when free 
from hulls, this product contains nearly 7 per cent of 
nitrogen. It is used in very large quantities, particu- 
larly in the southern states, where it is in abundant 
supply. It is, however, a most excellent cattle feed, 
and its use directly as a fertilizer will be reduced in 
proportion as its usefulness for this purpose is more 
fully appreciated. 

TAnseed meal is a material somewhat similar in 
character to cotton -seed meal. It contains on the 
average 5.5 per cent of nitrogen. The demand for 
this product for feeding purposes at good prices makes 
it, however, an expensive source of nitrogen. 

Castor pomace. — Castor pomace, the waste resulting 



NATURAL GUANOS 47 

from the extraction of oil from the castor bean, is also 
a valuable nitrogenous fertilizer. It contains, on the 
average, 6 per cent of this element, and decays 
rapidly in the soil. This product differs from the 
cotton -seed and linseed meal, in that it is not useful 
as a cattle food. Practically its only use is as a 
fertilizer. 

NATURAL GUANOS 

A series of nitrogenous products which constitute 
still another separate class, consists of the various 
natural guanos. These were formerly a very large and 
valuable source of nitrogen, though at the present 
time they are not commercially important, owing to 
the practical exhaustion of the best supplies. Of the 
guanos, the product obtained from Peru, or from 
islands on the coast of that country, is the richest in 
nitrogen. It is derived almost entirely from the ex- 
crement of sea birds, as well as from the remains of 
the birds themselves, and from various other animals. 
The composition of this guano is of a very complex 
character. The nitrogen exists largely as ammonia, 
combined with oxalates, urates, humates, sulfates, 
phosphates, carbonates, and to some extent in purely 
organic forms. In these forms the nitrogen is quickly 
available, and marvellous results are obtained from 
their use. 

Other guano deposits of considerable value, though 
poorer than the Peruvian, are found farther north on 
the coast of South America, as well as upon certain 



48 FERTILIZERS 

islands on the southwest coast of Africa. Ichaboe 
guano, for example, is at present exported, though it 
is a fresh deposit, and is annually collected for ship- 
ment. It is very inferior to the Peruvian guano, 
containing a very considerable amount of insoluble 
matter. At the present time, too, we have "bat guano," 
found in caves in Mexico and in some of the south- 
western states. This product is very inferior to the 
Peruvian guano iu its content of nitrogen, though the 
form is good, a considerable portion existing as nitrate. 
Owing to the very excellent results that were obtained 
from the early use of guanos, many attempts have 
been made to improve the lower grades obtainable at 
the present time, by the addition of nitrogenous matter 
of a higher rate of availability. These rectified, or 
fortified guanos, while containing nitrogen in good 
forms, cannot entirely substitute the original guanos, 
owing to the impossibility of adding forms identical 
with those existing in the natural product. That is, 
the total content of nitrogen in a rectified guano may 
be the same as in the genuine product, though the 
special forms and their proportions cannot be simulated. 
The distinctive value of the natural guanos is due to 
the fact that the nitrogen existed in a number of dif- 
ferently soluble compounds, which became available at 
different times in the soil, and thus constantly fed the 
plant with this element. The fact that nitrogen guanos 
gave such good results, is an evidence of the advan- 
tage of introducing different forms into artificial 
mixtures. 

It is argued that because of the very great value of 



NATURAL GUANOS 49 

guanos, which consist very largely of the excrement 
of fowls, that droppings of pigeons, particularly, and 
of domestic fowls should also possess a high value, 
and for this reason a rather fictitious value has been 
fixed upon these products. These products differ very 
materially from natural guanos, and it is due probably 
both to the character of the food eaten by the domestic 
fowl, and to the different methods by which the 
material is obtained. The birds producing the guanos 
feed largely upon fish, a highly nitrogenous food, 
resulting in an excrement richer in this element than 
that from the domestic bird, feeding largely upon 
vegetable matter ; and, besides, the former were accu- 
mulated in a hot, dry climate, which quickly absorbs 
the moisture contained in the fresh droppings, thus 
leaving it in a much drier state than is the case with 
the domestic product. 

It will be observed from the foregoing brief de- 
scription of the chief sources of organic forms of 
nitrogen, that a very wide variation occurs both in 
the composition or content of nitrogen in these pro- 
ducts, and in the availabilitj' of their nitrogen, or 
rapidity with which, under similar conditions, it is 
given up to plants. The fact that a substance contains 
nitrogen in considerable amounts and in an organic 
form, then, is not a sufficient guide as to its usefulness. 
Its mechanical condition, or physical form, must also 
be taken into consideration, and, other things being 
equal, the tougher and denser the substances, the 
longer the time required to decay, and hence the more 
slowly will the material feed the plant. 



50 FERTILIZERS 

AMMONIA COMPOUNDS 

As already stated, nitrogen does not feed the plants 
in organic forms ; it must first decay. The first pro- 
duct of the decay of a nitrogenous organic substance 
is ammonia, a combination of two elements, hydro- 
gen and nitrogen. As the organic animal or vege- 
table substance which contains carbon, hydrogen, oxy- 
gen and nitrogen in combination breaks up, the car- 
bon combines with part of the oxygen to form 
carbonic acid ; part of the hydrogen also combines 
with oxygen to form water, and the nitrogen combines 
with hydrogen to form ammonia. Yet even in this 
form, plants do not absorb it freely. Ammonia is in 
a better form than the organic material, because, in 
the first place, it is soluble in most of its combina- 
tions with other substances, and is thus readily dis- 
tributed in the soil, and in the second place, it is 
very liable to change. That is, its future availability 
is no longer dependent upon any mechanical or phys- 
ical form; every portion or pound of ammonia is as 
good as any other portion or pound. Ammonia, 
however, does not occur as a natural product, like 
the organic forms, blood, meat and fish. Commercial 
forms are the result of a manufacturing process, and 
they may exist as distinct chemical substances, as 
sulfate of ammonia, in which case the ammonia is 
combined with sulfuric acid; as chlorid of ammonia, 
in which case it is combined with hydrochloric 
acid; as nitrate of ammonia, in which case it is 
combined with nitric acid ; and as carbonate of Mm- 



SULFATE OF AMMONIA 51 

monia, in which ease it is combined with carbonic 
acid. 

Sulfate of ammonia is the only one of these com- 
pounds which can be now obtained at a sufficiently 
low cost to encourage its use as a fertilizer. Sulfate 
of ammonia is a chemical salt which, when pure, 
contains 21.2 per cent of nitrogen. In commercial 
forms, however, it usually contains about 20 per cent 
of nitrogen, and even this makes it the richest in 
nitrogen of any of the commercial nitrogenous pro- 
ducts. That is, every ton contains 400 pounds of 
nitrogen, and is thus richer by 60 pounds per ton 
than nitrate of soda, the next highest grade nitrog- 
enous product. Sulfate of ammonia is obtained from 
the dry distillation of animal bone in the manufacture 
of bone-black, from the distillation of coal in the 
manufacture of illuminating gas, and from coal in 
the manufacture of coke. The quantity now made is 
increasing annually, largely because of the improved 
methods used in the manufacture of coke, which per- 
mit the saving of the ammonia. The cost of nitrogen 
in this form is likely to be so much reduced in 
future as to encourage its very considerable use by 
fertilizer manufacturers. Its chief advantages are that 
it is very concentrated, therefore reducing the cost 
of handling ; it is always in the same form, a distinct 
and definite product, thus rendering its purchase a 
safe proceeding ; and it is very quick to act, thus 
making it a very useful form, especially for quick - 
growing crops. Its physical character is such as to 
permit its ready distribution in a mixture. 



52 FERTILIZERS 

NITRATE NITROGEN 

As previously stated, neither organic nor ammonia 
compounds containing nitrogen are capable of fully 
meeting' the demands of plants for this element. The 
first, or organic nitrogen, must pass through two 
changes, first to ammonia, and then to nitrate, and 
the ammonia must change to a nitrate. The nitrate is 
directly absorbed by plants, and the larger portion 
obtained by them is taken up in this form. Hence, 
from the standpoint of availability, nitrate nitrogen 
must be regarded as the most useful form. Like 
ammonia, too, a pound of it is as good as any other 
pound, from whatever product it may have been de- 
rived. It is a relatively concentrated material ; and 
as it is perfectly soluble, it readily distributes itself 
everywhere in the soil to which it may be applied. 

Nitrate of soda. — Although nitrogen as nitrate is 
not generally distributed as a natural product, vast 
deposits of crude nitrate of soda are found in the 
rainless districts of South America. These crude salts 
contain from 4 to 10 per cent of nitrogen, which are 
dissolved and re -crystallized before they are put upon 
the market, in order to remove as far as possible the 
impurities which are associated with them. The chem- 
ically pure salt, nitrate of soda, contains 16.47 per cent 
of nitrogen, and the commercial article, called "Chili 
saltpeter," contains from 15.5 to 16 per cent. The 
impurities which remain in it consist mainly of sodium 
chlorid, or common salt, which, together with moisture, 
causes a lower percentage in the commercial product. 



AVAILABILITY OF NITROGEN 53 

THE RELATIVE AVAILABILITY OP THE DIFFERENT 
FORMS OF NITROGEN 

From this discussion of the kind and source of 
nitrogenous fertilizer supplies, it is shown that the 
form of the nitrogen is an important factor in 
determining the rate at which the plants may obtain 
it. In the case of nitrate, the form is such as to 
enable the plants to take it up immediately. It is, 
therefore, theoretically the best, because as soon as 
it comes in contact with the roots, it is absorbed by 
them; there is no appreciable time required to enable 
the element to get into a condition to be taken up. 
Furthermore, its extreme solubility makes it possible, 
when moisture conditions are good, to reach every 
portion of the soil in which the roots are located, so 
that it is not only more available by virtue of its being 
in the right form, but because it readily goes to the 
place where the plant roots are. The next substance 
in order of availability is ammonia, and the rapid- 
ity with which ammonia will change to a nitrate 
makes it under many circumstances quite as useful. 
It possesses, too, one great advantage possessed by 
the nitrate, that of being soluble in water, and thus 
readily distributing itself throughout the surface soil. 
The difference in usefulness of these two forms seems 
to depend more largely upon the character of the 
season than upon the exact form. In a very wet 
season the nitrate is less useful, because liable to be 
washed below the reach of the roots, or lost alto- 
gether, and in a dry season it is more useful than 



54 FERTILIZERS 

the ammonia, because as soon as it is in solution it is 
capable of being absorbed. It must be remembered, 
however, that these two forms possess the further 
advantage over organic forms, that they are definite 
chemical compounds, which always possess the same 
characteristics, and under similar conditions they always 
act in the same way. If nitrogen is purchased as am- 
monia, the source of the nitrogen is not important; 
that is, whether derived in the manufacture of bone- 
black, or of illuminating gas, or coke, if it is ammonia, 
it is identical in its character. The same is true of 
nitrate — the original source of the nitrogen is imma- 
terial. 

The availability of organic forms, as already pointed 
out, depends upon the rapidity with which they will 
change to the nitrate form. Such products as dried 
blood, dried meat, dried fish and concentrated tank- 
age change rapidly, and are, therefore, good forms, 
while products like raw leather and horn meal are 
very slow to change. 

The practical point, and the one of prime impor- 
tance to the farmer, is, then, to know how to estimate 
the relative value or usefulness of these different pro- 
ducts, what is the rate of availability as compared 
with nitrate, and thus the relative advantage of 
purchasing the one or the other, at the ruling market 
prices. Relative values, however, cannot be assigned 
as yet, though careful studies of the problem have 
been made, chiefly by what are known as "vegetation 
tests," that is. tests which show the actual amounts of 
nitrogen that plants can obtain from nitrogenous pro- 



TSSTS OF AVAILABILITY 55 

ducts of different kinds, when they are grown under 
known and controlled conditions. The results so far 
obtained, while only serving as a guide, indicate that 
when nitrate is rated at 100 per cent, blood and 
cotton seed meal are about 70 per cent, dried and 
ground fish and hoof meal 65 per cent, bone and 
tankage 60 per cent, and leather and wool waste range 
from as low as 2 per cent to as high as 30 per cent. 
These figures furnish a fair basis for comparing the 
different materials, when used for the same purpose 
or under the same conditions. If, for example, the 
increased yield of oats due to the application of 
nitrate of soda is 1,000 pounds, the yield from blood 
and cotton -seed meal would be 700 pounds, the yield 
from dried ground fish and hoof meal would be 650 
pounds, from bone and tankage 600 pounds, and from 
leather, ground horn, and wool waste, from 20 to 300 
pounds. 

Conditions Which Modify Availability 

These figures alone are, however, not a suflBcient 
guide as to the kinds to buy under all conditions, 
since the usefulness of the different forms are again 
dependent upon such other conditions as the kind of 
crop, the season, and the object of the application. 
The kind of crop is an important factor, since certain, 
crops grow and develop quickly, while others grow for 
a comparatively long period ; the season, because the 
changes from organic forms to ammonia, or nitrate, 
only take place when the temperature reaches 37° F.^ 



56 FERTILIZERS 

and when in addition sufficient moisture is present. 
Hence, a material which might give excellent results 
when applied to a crop that grows through a long 
period in a climate where the season is very warm 
and moist, might be very unsatisfactory where the 
season is short, cold and dry. These are a few of 
the conditions which modify the rate of the decay of 
the same material. 

The object of the application should also be taken 
into consideration. The rate of the feeding of the 
plant with nitrogen in organic forms is measured by 
the rate of decay of the organic material containing 
it, while when nitrate is used, its feeding is direct. 
The result is really a sort of feeding of the soil in 
the one case, and a direct feeding of the plants in the 
other. Where the purpose is to get the largest pro- 
portionate increase in crop from the least amount 
applied, either the nitrate, or the ammonia, or the 
more active of the organic forms, would be likely to 
give the best returns. Whereas, if the object to be 
attained is not so much a large increased crop as it 
is increase in the future productive capacity of the 
soil in respect to this element, the slower -acting ma- 
terials will often answer the purpose quite as well as 
the use of the more active nitrate form, as in this 
form no insoluble combinations are formed, the 
nitrate is freely movable, and if the plants do not 
absorb it, and heavy rains come, the water contain- 
ing the nitrate is carried through the soil into the 
drains and the nitrogen lost. The disadvantage of 
the nitrate is, then, that there is a greater possibility 



CONDITIONS WHICH MODIFY A. VAILABILITT 57 

of loss from its use than from the use of materials 
which are either insoluble, or which are readily ab- 
sorbed. The ammonia, while perfectly soluble, is fixed 
by the other substances in the soil, and is not, there- 
fore, readily leached out, though if heavy applications 
are made the possibility is increased, because of the 
rapid change of the ammonia into the nitrate form. 
In the case of organic materials, the losses from 
leaching are seldom worthy of consideration in good 
practice, since an appreciable time is required, even 
in the case of the best forms, to change all of the 
nitrogen into ammonia, and then to a nitrate ; while 
in the case of the poorer forms, still more time is 
necessary to cause the change, and losses are not 
liable to occur. In the making up of fertilizers, all 
of these considerations should be carefully balanced, 
and it is the practice on the part of many manufac- 
turers to use a part of each of the three forms, so 
that a continuous feeding of the plant may be in- 
sured. Therefore, while the fact remains that fer- 
tilizers containing only the one form may not be the 
poorest, the chances are that those which contain all 
forms are likely to give more satisfactory results. 



CHAPTER IV 

PHOSPHATES — THEIR SOURCES, COMPOSITION AND 
RELATIVE VALUE 

Many farmers apply the term " phosphate " to all 
manufactured fertilizers, without regard to the kind 
and character of the fertilizing constituents con- 
tained in them. The term "phosphate" should only 
be applied to materials which contain phosphoric 
acid, and it does not necessarily imply that the 
phosphoric acid is in an available form. The term 
"superphosphate" implies that the phosphoric acid 
contained in the material is available. The phos- 
phates constitute a class of products from which 
superphosphates are made, and which are used in the 
manufacture of fertilizers that contain immediately 
useful or available phosphoric acid. The following 
discussion of phosphates is quoted from the author's 
" First Principles of Agriculture : " * 

The phosphoric acid in artificial manures is derived 
from compounds called "phosphates." In phosphates 
the phosphoric acid is united with lime, iron and 
alumina, forming phosphates of lime, iron and 
alumina, as the case may be. The phosphates of 



♦"First Principles of Acriculture." Silver, Burilett & Co., Boston, 1896. The 
qaotatiun comprises the entire discussion preceding "Phosphates as Sources of 
Phosphoric Add to Plants," except " Bone Tankage " and "Tennessee Phosphate."' 

(58) 



PHOSPHATE OF LIME 59 

lime are better calculated for the purpose, and are, 
therefore, used more largely than any other as a 
source of phosphoric acid, in the manufacture of 
artificial manures. 

The phosphates available for this purpose are not, 
however, pure salts, but exist in combination either 
with organic substances, or with minerals, or both, 
the content of phosphoric acid and its combination 
with other substances determining the usefulness of 
the phosphate to the manure -maker. 

The phosphoric acid in these materials is soluble 
with difficulty in the soil water ; and hence in their 
original condition, or in the crude raw forms, they 
give up this element in proportion as they decompose 
or decay in the soil. Those in combination with 
organic substances, either animal or vegetable, are, 
as a rule, more quickly useful as a source of phos- 
phoric acid than those composed entirely of mineral 
constituents. 



PHOSPHATE OP LIME, OR BONE PHOSPHATE — 
ANIMAL BONE 

The bones of animals are the chief source of phos- 
phates that exist in combination with organic matter, 
and were for a long time the main source for 
manurial purposes. 

Bone consists chiefly of three classes of sub- 
stances ; viz., moisture, organic matter, containing 
nitrogenous and fatty matter, and phosphate of lime, 
or bone phosphate — the proportion, particularly of 



60 FERTILIZERS 

the nitrogen and phosphoric acid, depending upon 
the kind of bone and the method of its treatment. 

Bone from the same kind of animal differs in 
composition according to the age of the animal and 
its location in the body. In a general way, the 
younger the animal the softer the bone, the poorer in 
phosphate of lime and the richer in nitrogen ; the 
older the animal, the richer in phosphate of lime and 
the poorer in nitrogen. The large and hard thigh 
bones of an ox, for instance, differ in composition 
from the softer and more porous bones of other parts 
of the body. 

The phosphate of lime of the harder bones is 
dense and compact ; that from the softer bone is 
more open and porous. The chief cause of variation 
in the composition of bones used as manure, how- 
ever, is due to the treatment they receive. This is 
recognized by manufacturers and dealers, and differ- 
ent names of brands are used to indicate the method 
of manufacture or treatment. As applied, however, 
they do not always correspond to the methods of 
treatment. 

Baw Bone 

The term "raw bone" is properly applied to bone 
that has not suffered any loss of its original con- 
stituents in the processes of its manufacture, and is 
for this reason highly regarded by farmers, who 
believe that it is purer than any other form. This is 
true in a large measure, though the fact that it is 



ANIMAL BONE 61 

raw bone is not altogether an advantage from the 
standpoint of usefulness. Raw bone too often con- 
tains considerable fatty matter, which makes it a diffi- 
cult process to grind it fine, and which also has a 
tendency to retard the decay of the bone in the soil. 
A considerable amount of fat also reduces propor- 
tionately the percentage of the valuable constituents, 
phosphoric acid and nitrogen. Good raw bone, free 
from meat and excess of fat, should contain on the 
average 22 per cent of phosphoric acid and 4 per cent 
of nitrogen. 

Fine Bone 

The trade terms "bone meal," "bone dust," and 
"fine bone," are used to indicate mechanical condi- 
tion, or fineness of division, and do not refer 
especially to composition. These names should not 
be taken as indicating the fineness without personal 
examination, since frequently the products do not, in 
this respect, correspond to the name. 

Boiled and Steamed Bone 

The larger portion of the bone used as manure 
has been boiled or steamed for the purpose of freeing 
it from fat and nitrogenous matter, both of which 
are products valuable for other purposes. The fat is, 
of course, of no value as a manure, and its absence 
is an advantage. The nitrogen, while useful as a 
manure, is extracted chiefly for the purpose of making 
glue and gelatine. 



62 FERTILIZERS 

By boiling or steaming, the bone suffers a loss of 
its original constituents, the chief result of which is 
to change the proportions of the nitrogen and phos- 
phoric acid contained in it. Steamed or boiled bone 
contains more phosphoric acid and less nitrogen than 
raw bone, and is also more variable in composition, 
the relative percentage of these constituents depending 
upon the degree of steaming or boiling to which the 
bone has been subjected. 

Bone that has been used for the purpose of 
making glue, where the chief object is to extract the 
nitrogenous matter, contains from 28 to 30 per cent 
of phosphoric acid and from 1% to 1% per cent of 
nitrogen. The steaming of bone, particularly when 
conducted at high pressure, also exerts a favorable 
effect upon the physical and mechanical character of 
the bone. It destroys its original structure, makes 
it soft and crumbly, and often reduces it to a finer 
state of division than can be readily accomplished by 
grinding ; and, since it is also free from fat, and is 
finer, it is more directly useful as a source of phos- 
phoric acid to plants than purer raw bone. 

In some cases, the fat is extracted from bone by 
means of such solvents as petroleum or benzine. 
These methods of extracting the fat have the ad- 
vantage of increasing the relative proportion of 
the nitrogen, this element not being attacked by 
the solvents. The more complete extraction of the 
fat and moisture by these methods also aids in 
the final preparation of the bone by grinding. Bone 
prepared in this way frequently contains as high 



TANKAGE 63 

as 6 per cent of nitrogen and 20 per cent of phos- 
phoric acid. 

The nature and composition of animal bone is 
such as to make it a valuable source of phosphoric 
acid ; and, while it is largely used with nitrogenous 
and potassic materials in the manufacture of artificial 
manures, its best use is, perhaps, in the fine ground 
form, particularly for soil improvement and for slow- 
growing crops. 

Phosphoric acid applied in this form gradually 
gives up nitrogen and phosphoric acid to the plant ; 
and its physical and chemical characteristics are such 
that it forms in the soil, during the growing season, 
no compounds more insoluble than the bone itself. 
Of all the phosphatic materials available as manure, 
bone is the only one that is now used to any extent 
without further treatment than simple grinding. 

Bone Tankage 

As already intimated in the discussion of nitrog- 
enous materials, certain products valuable for nitro- 
gen also contain considerable amounts of phosphoric 
acid. Among these, tankage is the most important, 
and six definite grades are now recognized in the 
trade — the richest containing as high as 18 to 19 per 
cent of phosphoric acid, or equivalent to 40 per cent 
bone phosphate ; the second containing 16 per cent 
phosphoric acid, equivalent to 35 per cent of bone 
phosphate ; the third containing 13% per cent of 
phosphoric acid, or equivalent to 30 per cent of bone 



64 FERTILIZERS 

phosphate ; the fourth, 11% per cent of phosphoric 
acid, or equivalent to 25 per cent of bone phosphate ; 
the fifth, 9 per cent phosphoric acid, or equivalent to 
20 per cent bone phosphate, and the sixth contain- 
ing about 7 per cent phosphoric acid, or equivalent to 
15 per cent bone phosphate. 

It will be observed that certain grades of tankage 
approach the composition of bone in their content of 
phosphoric acid ; the nitrogen increases as the phos- 
phoric acid decreases, as already pointed out in the 
discussion of nitrogenous materials. Since tankage 
is made from the residue remaining in the tanks 
used for boiling cattle heads, feet, clippings, and other 
refuse animal matter, it may be classed with boiled 
bone in reference to the quality of its phosphoric 
acid. Its agricultural value is further modified hy the 
fineness to which it is ground ; it is frequently sub- 
stituted for bone in the manufacture of fertilizers, 
where phosphate derived from bone is regarded as an 
important constituent of the mixture or brand. 

Other Organic Products 

There are also other products which should not 
be disregarded in a discussion of phosphates, though 
because of their content of other constituents they are 
primarily valued for them, rather than for the phos- 
phoric acid. A good example is the dried ground 
fish, which often contains as high as 8 per cent of 
phosphoric acid, or an equivalent of 17 to 18 per 'cent 
of bone phosphate of lime. The phosphoric acid in 



BONE-BLACK 65 

dried fish is frequently more available than in other 
organic forms, owing to the fact that in the drying 
of the scrap it is often necessary to add sulfuric acid 
to prevent putrefaction. On the average, more than 
one -half of the total phosphoric acid in this product 
is in an available form. 

The phosphoric acid contained in other nitrogenous 
products, as cotton -seed meal and castor pomace, 
while not large, is of some importance, as it is rela- 
tively more available than in raw bone or in tankage. 

Bone -black, or Animal Charcoal 

This material becomes an important source of 
phosphoric acid for artificial manures, after it has 
served its chief and first purpose in clarifying sugar. 
In making bone-black, only the best bones are used ; 
they are cleaned and dried, and placed in air-tight ves- 
sels, and heated until all volatile matter is driven off; 
the resultant product, which retains in part the original 
form of the bone, is then ground to a coarse powder ; 
it then becomes a bone charcoal, consisting chiefly of 
carbon and phosphate of lime, though also containing 
small amounts of magnesia and carbonate of lime. 

Bone-black, as received from the refineries, con- 
tains the impurities gathered there, consisting chiefly 
of vegetable matter and moisture. It is somewhat 
variable in composition, containing from 32 to 36 
per cent of phosphoric acid and a small amount of 
nitrogen. It decays slowly in the soil, and is not now 
used to any extent directly as a manure. 



66 FERTILIZERS 

Bone -Ash 

Bone -ash is an excellent, though not large, source 
of phosphoric acid. It is exported in considerable 
quantities from South America, where the bones are 
burned and the bulk reduced, in order to facilitate 
transportation. It does not contain nitrogen, and is 
more variable in composition than bone-black, though 
usually somewhat richer in phosphate of lime. Good 
samples contain from 27 to 36 per cent of phos- 
phoric acid. 

Bones themselves, and the phosphates derived 
from bones, constitute a class differing from other 
phosphates used in making manures, in that they are 
derived directly from organic materials and, as a 
class, they possess characteristics, due to this fact, 
which render them more useful than those derived 
from purely mineral sources. 

MINERAL PHOSPHATES 

These constitute a class of products differing from 
those of immediate or recent animal origin mainly in 
the fact that they are not combined with organic mat- 
ter, and are more dense and compact in their struc- 
ture. They occur in several different forms, and are 
procured from distinct sources. 

South Carolina Rock Phosphates 

These are found both on the land and in the beds 
of rivers in the vicinity of Charleston, S. C, and are 



SOUTH CAROLINA ROCK PHOSPHATES 67 

sometimes called "Charleston phosphates." The de- 
posits vary in thickness from one to twenty feet, 
through which the phosphate is distributed in the 
form of lumps or nodules, ranging in weight from an 
ounce to over a ton. These nodules are irregular, 
non- crystalline masses, often full of holes, which con- 
tain clay or other non-phosphatic materials. That 
obtained from the river is called "river phosphate," 
or "river rock;" and that from the land, "land phos- 
phate," or "land rock." The two varieties do not 
differ materially in composition, particularly in the 
content of phosphoric acid. 

The rock contains from 26 to 28 per cent of phos- 
phoric acid. Its uniformity, in connection with the 
fact that it contains but small percentages of com- 
pounds of iron and alumina, minerals which prevent 
its best use by the manufacturer, make it a highly 
satisfactory source of phosphoric acid. 

The river rock is secured by dredging ; that from 
the land is largely dug. In either case it is washed 
to remove the adhering matter, and then dried, when 
it is ready for grinding or shipment. South Carolina 
rock phosphate, when very finely ground, is called 
"floats." It is sometimes used upon the land in this 
form, and when used for certain crops, as turnips, for 
example, and on certain soils, notably those wet and 
heavy and rich in vegetable matter, very satisfactory 
returns are obtained. 

These deposits were first worked in 1868, though 
the presence of phosphate at this point was known at 
a much earlier date. 



68 fER TI L [ZERS 

Florida Phosphates 

The presence of phosphate in commercial quanti- 
ties in Florida was discovered in 1888, since which 
time very great progress has been made in developing 
the deposits. The deposits occur in a number of 
forms, — first, "soft phosphate," a whitish product, 
somewhat resembling clay, and largely contaminated 
with it; second, "pebble phosphate," consisting of 
hard pebbles, occurring both in river beds and upon 
the land, and mixed with other materials ; and third, 
"rock," or "bowlder phosphate," which occurs in the 
form of stony masses or bowlders, both large and 
small. These three forms also differ widely in com- 
position, both in reference to their content of phos- 
phoric acid and in respect to the presence of other 
minerals. 

The soft phosphate is the poorest in phosphoric 
acid. It is easily prepared, and is largely used directlj^ 
upon the laud. It is also the most variable in com- 
position, ranging from 18 to 30 per cent. The pebble 
rock is also variable in composition, though, when 
washed free of sand and clay, it is richer in phos- 
phoric acid than the soft variety. Good samples con- 
tain as high as 40 per cent and over of phosphoric 
acid. The bulk of the "Florida phosphate" is be- 
lieved to exist in the pebble form. 

The rock or bowlder phosphate, though apparently 
much less in amount, is more uniform in composition, 
and is much richer than either of the othfr forms. 
The elean, dry bowlder phosphate often contains as 



OTHER MINERAL PHOSPHATES 09 

high as 40 per cent phosphoric acid, far exceeding in 
richness the South Carolina rock superphosphate. 



Canadian Apatite 

This material is a crystallized rock of true mineral 
origin, and occurs associated to a greater or less ex- 
tent with other materials. It is, therefore, not uni- 
form in character, the phosphoric acid varying 
according to the amount of the other substances 
present. 

It is mined in the provinces of Quebec and Onta- 
rio, and separated into various grades at the mines. 
The mining is expensive, and the necessity for grad- 
ing in addition makes the cost of production propor- 
tionately high. The highest grade of this phosphate 
is very pure, containing 40 per cent of phosphoric 
acid. 

Tennessee Phosphate 

The phosphate deposits in Tennessee were discov- 
ered in November, 1894, since which time they have 
been exploited and a rapid development made. This 
phosphate differs from the phosphate of South Caro- 
lina and Florida in that it does not exist as nodules, 
pebbles or bowlders, but in veins and pockets, and, 
therefore, does not need to be washed and dried 
previous to its treatment. While the phosphates from 
the various deposits are not uniform in their com- 
position, it is possible to secure large quantities that 



70 h'ERTtLIZERH 

equal or exceed 30 to 32 per cent of phosphoric acid, 
or 70 per cent or over of bone phosphate, and that 
are relatively free from deleterious substances, thus 
making them not only a rich but a valuable source 
of supply for the manufacturers of superphosphates. 

Iron Phosphate, or Thomas Phosphate Powder 

This is a waste product from the manufacture of 
steel from phosphatic iron ores, by what is known 
as the "basic process." It is sold under several 
names, as " Thomas phosphate meal," " phosphate 
slag," "basic slag," and "odorless phosphate." It 
is produced in large quantities in England, France 
and Germany, and in those countries is not only one 
of the cheapest sources of phosphoric acid, but is 
regarded as a very valuable product. It contains 
from 15 to 20 per cent of phosphoric acid in the 
form of phosphate of lime, in connection with large 
amounts of lime and oxide of iron. It is used almost 
altogether in the form of a fine powder, since it is 
not suitable for the purposes of the manufacturer. 

Phosphatic Chuanos 

Previous to the discovery of the phosphates in 
South Carolina, these guanos were a very important 
source of phosphoric acid. They are now but little 
used in this country. They are obtained from the 
rainless districts of the world, chiefly from the islands 
bordering the coast of South America and from the 
West Indies. They are derived from the excrements 



PHOSPHATES AS FERTILIZERS 71 

of birds, and frequently include considerable organic 
matter containing nitrogen. 

The Peruvian guano of earlier times was particu- 
larly rich in the best forms of nitrogen. The purely 
phosphatic guanos are rich in phosphoric acid, and are 
excellent materials. Like the iron phosphate, they are 
not suitable for the manufacture of artificial manures. 

PHOSPHATES AS SOURCES OP PHOSPHORIC ACID 
TO PLANTS 

The phosphates mentioned constitute what are called 
"raw materials," and, with the exception of bone, are 
not largely used directly, or without further treatment 
to render the phosphoric acid more soluble, and thus 
more immediately available to plants. As already 
stated, the phosphoric acid in them becomes food in 
proportion to the rapidity of deca}', which is influenced 
both by the character of the material and the fineness 
of its division. Fine materials, too, permit of a more 
even distribution, thus bringing more particles of 
phosphate in contact with the roots of plants. 

As already stated, a phosphate is a substance in 
which the phosphoric acid is combined with lime, iron 
or alumina. The phosphates of lime are the only ones 
that are used to any extent in the manufacture of arti- 
ficial fertilizers. The phosphoric acid contained in 
animal bone is in the form of phosphate of lime, 
hence the term "bone phosphate of lime" has been 
applied to all phosphates that contain their phosphoric 
acid as phosphate of lime. In fact, statements of 



72 FERTILIZERS 

analysis of iron and alumina phosphates are frequently 
expressed in terms of phosphate of lime. That is, 
the content of phosphoric acid is stated as equivalent 
to a certain percentage of bone phosphate, the term 
expressing the total amount of combined phosphoric 
acid; as, for example, a bone which contains 20 per 
cent of phosphoric acid, which is the average content 
in good bone, is equivalent to 43.60 per cent of phos- 
phate of lime. 

All phosphates are insoluble in water, but, as 
phosphates, they are not capable of feeding the plant 
directly; they must first decay. Hence, the useful- 
ness of a phosphate depends upon the rate of decay, 
or time required to change to such a form as to be- 
come available to the plant. The rapidity with which 
a phosphate will feed the plant depends upon a num- 
ber of conditions, chief among which are, first, the 
character of the substance itself; second, the fine- 
ness of its division ; third, the character of the soil 
to which it is applied; and fourth, the kind of crop 
for which it is used. 

The Influence of Source of Phosphate Upon 
Availability 

The chief point to be observed in the first case, 
is whether the substance is animal or vegetable, or 
whether it is mineral. Phosphates of immediate 
animal or vegetable origin decay more rapidly than 
purely mineral phosphates, because of the greater 
tendency of the organic matter with which the phos- 



AVAILABILITY OF PHOSPHATES 73 

phate is associated to respond to the action of the 
natural agencies which cause decay. A bone, for 
example, if kept in a suitable condition of moisture 
and warmth, will soon begin to rot, the rotting 
affecting not only the animal matter, but more or 
less the phosphatic matter with which it is so 
closely identified, the fermentation primarily attack- 
ing the organic substances, but exercising a greater 
or less solvent effect upon the phosphates. 

In the case of the mineral substances, the rate of 
decay is usually much slower, because there is no 
organic fermentation. The material changes or is 
broken up only by virtue of the action of the natural 
solvents, air and water, and solvent substances in the 
soil. Furthermore, the phosphate of the animal bone 
is always a phosphate of lime, which, while not 
soluble, is in itself more readily attacked by the 
natural agencies than a mineral phosphate which has 
associated with the bone phosphate other minerals 
that are not readily attacked by those agencies. That 
is, the mineral phosphates, while they are made up 
chiefly of phosphate of lime, are associated with other 
minerals, as iron and alumina, that are more slowly 
attacked than the phosphate of lime itself, and to 
some extent, too, prevent the full effect of the sol- 
vents, rather than encourage their action, as is the 
case with bone. 

Influence of Fineness of Division 

In the second place, fineness of division has an 
important bearing upon availability, since the finer 



74 FERTILIZERS 

the substance is ground, the greater will be the sur- 
face area exposed to the natural agencies which cause 
decay. Thus the application of a coarsely ground 
phosphate may not show any results the first season, 
while the same substance ground to a powder may 
have a good effect the first season ; that is, its fine- 
ness permits of the solubility of a considerable portion 
of its phosphoric acid. 

The Characier of Soil as a Factor Influencing 
Availability 

In the third place, the kind of soil to which the 
phosphate is applied may influence the rate at which 
the plants may obtain it. A soil which is open and 
porous, and thus permits the free access of air and 
circulation of water, and one which contains a large 
portion of other matter capable of decay, vegetable or 
animal, presents more favorable conditions for the 
solubility of phosphates than one which is close and 
(•ompact in texture and purely mineral in its charac- 
ter, thus preventing the free access of air and water, 
and in which no organic changes are taking place. 
In the one case the conditions are such as to favor 
the action of the natural agencies, and in the other 
they are such as to retard their action. 

Influence of the Kind of Crop 

In the fourth place, the value or usefulness of 
phosphates is measured to some extent by the charac- 



AirATL,ABTLTTr OF PHOSPHATES 75 

teristics of the plant or crop to which they are ap- 
plied. Plants differ in their power of acquiring food. 
Certain plants are able, because of their peculiar root 
system, or period of growth, to appropriate food more 
readily from insoluble sources than others. 

General Considerations 

All these considerations must be observed in 
determining the usefulness of a phosphate. It is 
believed by experienced farmers, though not abso- 
lutely confirmed by experimental inquiry, that animal 
bone, for example, is far superior, as a source of 
phosphoric acid, for most crops, to the mineral phos- 
phates, though both may be ground to the same 
degree of fineness ; and also, that the finer the 
bone is grouud, the more rapidly will it give up its 
phosphoric acid. 

Laboratory tests show that the phosphoric acid in 
bone, while insoluble in water, may be partly dis- 
solved at a certain temperature by a neutral solution 
of ammonium citrate. This medium is used to de- 
termine what is called "available" in other phos- 
phatic products. The rate of solubility in this medium 
is measured by the method of preparation of the bone 
and its fineness, the phosphate in raw bone meal of 
the same fineness showing rather a lower rate of 
solubility than the phosphates in steamed bone. The 
phosphate in the finest steamed bone is much more 
soluble than that in the coarser grades. This measure 
of the rate of solubility of bone, while not, perhaps, 



7b FERTILIZERS 

showing the exact rate at which the plants may 
obtain it, is a fairly safe guide in its use for most 
crops, as compared with those mineral phosphates 
which are not perceptibly soluble in this medium. 
The range of solubility of different kinds and grades 
of bone is from 20 to 75 per cent, and the average 
of a large number show about 30 per cent soluble 
in citrate of ammonia, which would be called "avail- 
able" if found in mixed fertilizers, and probably can 
be as safely depended upon as the available shown 
in other products. 

In any case, animal bone, or finely ground mineral 
phosphates, cannot be depended upon to fully meet the 
needs of quick -growing crops for phosphoric acid, but 
may answer an excellent purpose where the object is 
to gradually improve the soil in its content of this 
constituent, as well as to supply such crops as are 
continuous, or that grow through long periods, as, 
for example, meadows, pastures, and orchard and 
vineyard crops. 

As to the specific substance, the iron phosphate, 
or Thomas phosphate powder, experiments in Europe 
have shown that it possesses a higher rate of availa- 
bility than other phosphates which are insoluble in 
water, but which show the same rate of solubility 
in ammonium citrate, though its solubility, or 
availability, is measured to some extent by the degree 
of fineness to which it is ground; and it is believed 
that its special form, the tetra- calcic, also exercises a 
considerable influence upon the rate of availability, 

European vegetation and field experiments show 



AVAILABILITY OF PHOSPHATES 77 

pretty clearly that two parts of phosphoric acid from 
the Thomas phosphate powder are approximately 
equivalent to one part from soluble phosphoric acid, 
and that this phosphate is especially useful on wet, 
marshy soils and those poor in lime. Experiments 
conducted in this country practically confirm these 
conclusions. 

The relative availability of the phosphates in the 
natural guanos has also been shown to be somewhat 
higher than in other insoluble phosphates. These 
latter substances for this reason possess a distinct 
value over others for certain classes of crops, as, for 
example, cranberries, where the soluble phosphates 
would be liable to be washed out, and where the 
organic phosphates would be liable to float on the 
surface of the water, and also where lands are cold 
and sour, and not readily fermentable. 

The practical point, however, to the farmer, is the 
amount of increase that he may obtain from a certain 
definite expenditure, a matter which will be discussed 
later, in the discussion of the use of fertilizers for the 
yarious crops. 



CHAPTER V 

SUPERPHOSPHATES — POTASH 

The different phosphates mentioned in the pre- 
vious chapter constitute the sources of supply for 
the manufacture of commercial fertilizers. That is, 
with the exception of animal bone, Thomas phos- 
phate powder and natural guanos, they are used more 
extensively for this purpose than directly on the land 
in their raw state. They are the raw materials from 
which the manufactured phosphatic fertilizers are de- 
rived. The purpose of the manufacture is to con- 
vert them into a form in which the phosphoric acid is 
immediately available, and thus directly useful to the 
plant. The term "available" in this case is used in the 
same sense as in the discussion of the forms of nitro- 
gen (Chap, iii.), and it means that when the phos- 
phoric acid is in this form, the plants may acquire it 
immediately. 

INSOLUBLE PHOSPHORIC ACID 

Phosphate of lime is, chemically speaking, a salt 
capable of existing in various forms, the form measur- 
ing in large degree the rate of availability. The 
phosphate of lime, as it exists in the animal bone and 
mineral phosphates, for example, consists of three 

(78) 



FORMS OF PHOSPHORIC ACID 79 

parts of lime and one of phosphoric acid. This is 
the insoluble form. It is not immediately available, 
and because of the three parts of lime to one of 
phosphoric acid, which it contains, it is also called 
tricalcic, tribasic, or bone phosphate, and is graph- 
ically expressed in the accompanying formula; 

Lime 

Lime Phosphoric Acid 

Lime 

That is, in each molecule, however small, there are 
three parts of lime and one part of phosphoric acid. 

SOLUBLE PHOSPHORIC ACID 

In another form, the phosphate consists of one part 
of lime and one of phosphoric acid, two parts of the 
lime in the tricalcic form being replaced with water. 
This form is called monobasic, or monocalcic. It is 
a saturated phosphate. There could be no less than 
one part of lime to one of phosphoric acid, and such 
phosphates are called acid phosphates, or superphos- 
phates. The combination of the lime and phosphoric 
acid may be shown as follows: 

Lime 

Water Phosphoric Acid 

Water 

This form is completely soluble in water and im- 
mediately available, and when applied to the soil 
readily distributes itself everywhere, thus making it 
more useful than any other form. 



80 FERTILIZERS 



REVERTED PHOSPHORIC ACID 

Another form of phosphate consists of two parts 
of lime and one part of phosphoric acid, and is called 
dicalcic, dibasic, or reverted, One part of the lime 
in the insoluble is replaced by an equivalent of water, 
and is expressed as follows: 

Lime 

Lime Phosphoric Acid 

Water 

The reverted form, which means a going back from 
the soluble toward the insoluble form, is also insoluble 
in water, but is readily soluble to the roots of plants. 

It was formerly supposed that these three were 
the only forms in which phosphoric acid existed, but 
another form, in which four parts of lime are com- 
bined with one of phosphoric acid, and thus called 
tetrabasic, or tetracalcic, has been found quite re- 
cently to exist in the Thomas phosphate powder: 

Lime 

, . Phosphoric Acid 

Lime 

Lime 

This form is insoluble in water, though it has 
been found to be more available than the insoluble 
tribasic form. 

HOW SUPERPHOSPHATES ARE MADE 

Any material which contains a high content of the 
tricalcic or bone phosphate, 60 per cent or over, is 



TEE MANUFACTURE OF SUPEBPHOSPHATES 81 

suitable for the manufacture of superphosphates, pro- 
vided it does not possess a too high content of dele- 
terious substances. In the manufacture of superphos- 
phates, the phosphate is first ground to a fine powder, 
then mixed with sulfuric acid. The acid dissolves the 
phosphate, and two parts of the lime which are com- 
bined with the phosphoric acid in the tricalcic form 
are first set free, and then combined with the sulfuric 
acid, making a superphosphate (monocalcic), and a 
sulfate of lime or gypsum. That is, in this process, 
two of the three parts of the lime combined with the 
phosphoric acid to form the insoluble phosphoric 
acid, are removed, thus leaving one part of the lime 
combined with the phosphoric acid, making the super- 
phosphate. A pure superphosphate is, therefore, a 
mixture of soluble phosphate and of sulfate of lime 
or gypsum. 

The Difference in the Superphosphates made 
from the Different Materials 

In the early use of superphosphates, the chief raw 
material was animal bone. The superiority of the 
bone superphosphate, or dissolved bone, as it was 
called, over the raw bone, was manifest at once, and 
the familiarity with genuine bone superphosphates 
thus early acquired by farmers was, perhaps, quite 
as influential as any other in creating a prejudice in 
favor of their continued use in preference to super- 
phosphates derived from mineral phosphates. The 
opinion that the bone superphosphate is "the best" 



82 FERTILIZERS 

is held even at the present day, notwithstanding th3 
equally satisfactory results that have been obtained 
from the use of the superphosphates from other 
sources. 

Soluble Phosphoric Acid Chemically Identical, 
from Whatever Source Derived 

Chemically speaking, the soluble phosphoric acid 
produced by the action of sulfuric acid upon mineral 
phosphates is identical with the soluble phosphoric 
acid derived from animal bone, and if the soluble 
from each could be separated from the other sub- 
stances with which they are associated, there would 
be no difference whatever in the results of their use. 
They are identical ; just as much so as ammonia 
obtained in the manufacture of bone-black from 
bones is identical with the ammonia obtained in the 
manufacture of illuminating gas or coke. In many 
cases, doubtless, superior results have been obtained 
from the use of the animal bone superphosphate, 
though this has not been due to anj' inferiority of the 
available phosphoric acid in the mineral superphos- 
phate, but rather to the fact that substances have 
been compared that are not strictly comparable. They 
are radically different. The one contains, in addition 
to its available phosphoric acid, the only fertilizing 
ingredient in the mineral superphosphate, considerable 
nitrogen, and, moreover, it contains its insoluble phos- 
phoric acid in a form that is liable to decay more 
rapidly than the insoluble in the mineral phosphate. 



PHOSPHATES AND SUPERPHOSPHATES 83 

Soluble phosphoric acid is a definite compound. The 
source from which it is derived does not influence 
this point, and the action of a definite quantity is 
also identical when conditions are similar. 



PHOSPHATES AND SUPERPHOSPHATES ARE NOT 
IDENTICAL 

The idea in the term "phosphate" should also be 
kept distinct from that conveyed by the term "super- 
phosphate." The first means, and should be applied 
to, any material containing as its chief constituent 
phosphoric acid; the other means, and should be ap- 
plied to, any material containing soluble phosphoric 
acid as its chief constituent. The phosphates which 
have already been described are each capable of being 
converted into a superphosphate, as animal bone super- 
phosphate, South Carolina rock superphosphate, bone- 
black superphosphate, bone-ash superphosphate, Florida 
rock superphosphate, and Tennessee rock superphos- 
phate. These superphosphates vary in their content 
of soluble phosphoric acid, due both to the variation 
in the content of the phosphoric acid in the phosphates 
used as raw materials, and to the excellence of the 
method of manufacture. In other words, the super- 
phosphates, while practically identical in so far as the 
form of phosphoric acid is concerned, vary in their 
total content of soluble phosphoric acid. For ex- 
ample, superphosphates made from the animal phos- 
phates, as bone-black, bone -ash, etc., are usually 
richer in soluble phosphoric acid than those made 



S4 FERTILIZERS 

from animal bone, or from many of the mineral 
phosphates, because these phosphates are of such a 
character as to enable the manufacturer to convert all 
the phosphoric acid present into a soluble form, and 
at the same time to secure a fine, dry product, that 
may be readily handled — an important consideration 
in making superphosphates. 

"Mineral phosphates, both because of their hard- 
ness and of the presence of other minerals, which are 
attacked by the acid, are less easily dissolved, and 
require more acid in proportion to the phosphate 
present than those from organic sources. They are 
also less absorbent, preventing the acid from perme- 
ating the mass of the material, and hence it is more 
difficult to secure good condition when sufficient acid 
is used to dissolve the phosphate. In making super- 
phosphates from these materials, less acid is used than 
is required to completely dissolve the phosphates, and 
.there is, therefore, always present in them more or 
less of the insoluble phosphoric acid. 

"In the case of animal bone, too, less sulfuric acid 
is used than is required to completely dissolve the 
phosphoric acid. Otherwise, a gummy, sticky product 
would result, due largely to the organic matter in the 
bone. The insoluble phosphoric acid in bone, bone- 
black, and bone -ash superphosphates is, however, of 
greater value than the insoluble in the mineral phos- 
phates, for reasons already given. 

"In superphosphates, too, there is nearly always 
present a greater or less aiiiouut — depending upon the 
material — of the second form of phosphoric acid, the 



PffOSPHATJSS AND SUPEEPHOSPHATES 85 

dicalcic, reverted or retrograde. This form usually 
exists in the greatest amounts in those made from 
mineral phosphates, which is believed to be due either 
to the soluble acting upon the insoluble portions, or 
to the presence of oxide of ii-on and alumina, which 
combine with a portion of the soluble phosphoric acid. 
The soluble goes back to the less soluble dicalcic 
form."* 

Aikman states the matter very clearly in the fol- 
lowing words : t "A change which is apt to take place 
in superphosphate after its manufacture is what is 
known as 'reversion of the soluble phosphate.' Thus 
it is found that on keeping superphosphate for a 
long time the percentage of soluble phosphate becomes 
less than it was at first. The rate at which this 
deterioration of the superphosphate goes on varies in 
different samples. In a well-made article, it is prac- 
tically inappreciable, whereas in some superphosphates, 
made from unsuitable materials, it may form a con- 
siderable percentage. The causes of this reversion 
are two -fold. For one thing, the presence of unde- 
composed phosphate of lime may cause it. This 
source of reversion, however, is very much less im- 
portant than the other, which is the presence of iron 
and alumina in the raw material. When a soluble 
phosphate reverts, what takes place is the conversion 
of the monocalcic phosphate into the dicalcic. 

" Where reversion is due to the presence of iron and 

♦"First Principles of Agriculture." Silver, Burdett & Co., Boston. 

t" Manures and Manuring." An excellent English work, of recent issue. 



86 FERTILIZERS 

alumina in the raw material, the nature of the reac- 
tion is not well understood, and is, consequently, not 
so easily demonstrated as in the former case. Where 
iron is present in the form of pyrites, or ferrous 
silicate, it does not seem to cause reversion. It is 
only when it is present in the form of oxide (and in 
most raw phosphatic materials it is generally in this 
form) that it causes reversion in the phosphate." 

Aikman also discusses the value of reverted phos- 
phates, showing the estimation in which they are 
held in England: "The value of reverted phosphate 
is a subject which has given rise to much dispute 
among chemists. That it has a higher value than the 
ordinary insoluble phosphate is now admitted, but in 
this country, in the manure trade, this is not as yet 
recognized. At first it was thought that it was im- 
possible to estimate its quantity by chemical analysis. 
This difficulty, however, has been overcome, and it is 
generally admitted that the ammonium citrate process 
furnishes an accurate means of determining its amount. 
Both on the continent and in the United States 
reverted phosphate is recognized as possessing a 
monetary value in excess of that possessed by the 
ordinary insoluble phosphates. The result is, that 
raw. mineral phosphates containing iron and alumina 
to any appreciable extent are not used in this country, 
although they do find a limited application in America 
and on the continent." 

As stated by Aikman, the reverted phosphoric acid 
due to the presence of undecomposed phosphate, as 
well as the reverted due to the presence of iron and 



DOUBLE SUPERPHOSPHArES 87 

alumina, are recognized by the chemists in this coun- 
try, and this recognition is strongly encouraged by 
commercial interests, because of the fact that our 
mineral phosphates contain, as a rule, iron and 
alumina, which by their action reduce the percentage 
of the soluble. The method of chemical analysis 
which has been adopted by the American Association 
of Official Agricultural Chemists recognizes this form, 
and it is, therefore, determined and included in the 
"total available" in statements of analysis. In one 
state, New Jersey, the law requires that the dicalcic 
form only shall be recognized, and it assumes that the 
agricultural value of this form is equal to that of the 
soluble. 

DOUBLE SUPERPHOSPHATES 

In addition to the superphosphates made directly 
from the various materials mentioned, a special sub- 
stance, called a "double superphosphate," which may 
be made by dissolving low-grade phosphates with an 
excess of dilute sulfuric acid, or those too poor in 
phosphoric acid to make a high-grade superphosphate. 
The dissolved phosphoric acid thus obtained, together 
with the excess of sulfuric acid, are separated from 
the insoluble materials by filtering, which acids, after 
concentration, are then used for dissolving the better 
phosphates ; and because the acids used for dissolving 
the phosphates contain phosphoric acid, the content 
of available phosphoric acid in these products is 
more than double that contained in the ordinary 



88 FERTILIZERS 

products. These are mostly manufactured in Europe, 
and are not used to any extent in this country. They 
possess the advantage of containing a minimum of 
impurities and a maximum of phosphoric acid in a 
soluble form. 

In stating the composition of superphosphates, the 
three forms of phosphoric acid are all recognized. 
The sum of the soluble and reverted forms is called 
the "total available," because these, as already stated, 
are regarded as immediately useful to the plant. In 
commercial transactions in mineral superphosphates, 
the total available only is regarded, — the content of 
insoluble being ignored. 

CHEMICAL COMPOSITION OF SUPERPHOSPHATES 

As already stated, the composition of the super- 
phosphates varies according to the richness in phos- 
phoric acid of the phosphates used, and according 
to the character of the material. Bone -ash and bone- 
black superphosphates are more uniform in composi- 
tion than those derived from the mineral phosphates, 
and the phosphoric acid is practically all in the solu- 
ble form. They contain on the average about 16 per 
cent of total available phosphoric acid. The mineral 
or rock superphosphates differ from these in being 
more variable in their total content of available, and 
in showing wider variations in the proportions of 
reverted, the latter depending upon the skill in manu- 
facture, as well as the character of the original 
material. Well made South Carolina rock superphos- 



COMPOSITION OF SUPERPHOSPHATHS 89 

phates contain from 12 to 14 per cent of total availa- 
ble, of which 1 to 3 per cent is dicalcic, or reverted. 
There are several grades of the Florida rock super- 
phosphates, due to the variation in the composition of 
the various raw phosphates. The pebble superphos- 
phates are the richest, often containing as high as 16 
or 17 per cent of total available, with varying percent- 
ages of reverted and insoluble. The Tennessee super- 
phosphates also vary from the same cause, the richest 
showing as high as 16 to 18 per cent of total availa- 
ble. The concentrated, or double superphosphates, may 
contain as high as 45 per cent of available, practically 
all of which is soluble. The superphosphates made 
from animal bone are usually more variable in their 
composition than those made from bone-black, bone- 
ash or mineral phosphates, and the variation is due 
both to the variability of the raw materials and the 
difficulties involved in their change into superphos- 
phates. The usual guarantee on an animal bone 
superphosphate is 12 per cent available, and from 3 to 
5 per cent of insoluble. These superphosphates also 
differ from the mineral superphosphates in containing 
nitrogen in addition to their phosphoric acid. They 
are, therefore, really ammoniated superphosphates. 

Well Made Superphosphates Contain no Free Acid 

In the earlier history of the use of acid phosphates, 
or rock superphosphates, objections were urged against 
them, and are to some extent at the present time, 
because of the supposed deleterious effects of the 



90 FERTILIZEBU 

acids contained in them, and these objections were 
undoubtedly encouraged, — certainly not discouraged, — 
by those manufacturers who used only genuine bone 
superphosphates. While the objections on this ground 
may have had some basis in earlier times, before their 
manufacture was well understood, there can be no 
rational objection to their use at the present time, 
when they are properly made ; for while in fresh super- 
phosphates a portion of the phosphoric acid may be in 
the form of "free" phosphoric acid, this form in ordi- 
nary superphosphates is practically all combined with 
lime or other minerals before it is placed upon the 
market, and there is really no more "free" acid in 
the rock superphosphate than in any other. It is quite 
likely this erroneous impression arose from the fact 
that strong sulfuric acid was used in the manufacture, 
and the belief existed that it remained as such. No 
free sulfuric acid exists in well made superphosphates. 
The sulfuric acid is combined with the lime to form 
gypsum, as already described, and the free phosphoric 
acid combines with the lime to form either a soluble 
or a reverted form. 

Phosphoric Acid Remains in the Soil Until Taken 
Out by Plants 

The phosphoric acid in superphosphates, though 
soluble in water, is not readily washed from the soil. 
The real object of making it soluble is to enable its 
better distribution. If it were possible to as cheaply 
prepare the dicalcic or reverted form as the soluble, it 



THJS FIXATION OJf PHOSPHOBIU ACID 91 

would, perhaps, be quite as useful from the standpoint 
of availability. After the soluble is distributed in the 
soil, it is fixed there by combining with the lime and 
other minerals present. It is believed that it assumes, 
first, by the larger relative proportion of lime usually 
present in soils, the dicalcic form, though it is not 
positively certain that in the presence of an abundance 
of lime, or that in time, it may not assume the in- 
soluble tricalcic form. The soluble phosphoric acid 
may also combine with the iron and alumina in the 
soil, and form phosphates of these elements, though 
recent investigations lead to the conclusion that these 
conditions are much more rare than was at one time 
supposed. The time required for the fixing of the 
phosphoric acid, as well as the form it may eventually 
assume, depends chiefly upon the character and com- 
position of the soil. In those rich in lime, the fixa- 
tion is most rapid, though in no sense is the fixation 
immediate, and in such soils the fixation is probably 
largely completed in the course of a week. On clay 
soils, containing a low percentage of lime, and in 
light soils that contain little clay or organic matter, 
the fixation is much slower, though even in these the 
chances are that no serious loss of phosphoric acid 
occurs. Seldom do we find more than traces of phos- 
phoric acid in drainage waters, even when heavy 
applications of soluble phosphoric acid are followed 
by heavy rains. The fact that the fixing power of 
soils practically prevents the loss of phosphoric acid 
should, however, not be used as an argument in favor 
of the careless use of superphosphates. 



92 FERTILIZERS 



POTASH SALTS 



Until the discovery of the mines of crude potash 
salts in Stassfurt, Germany, in 1859, and which have 
been worked since 1862, the chief source of potash 
for farm plants, other than that contained in yard 
manures, was wood ashes. The supply from this 
source now, however, is sufficient to meet all imme- 
diate as well as future demands, since the deposits 
are practically inexhaustible, though notwithstanding 
the abundance of the supply and the improvements 
made in the methods of utilizing the various salts, 
other than potash, contained in the deposits, it is the 
only fertilizer constituent which has remained prac- 
tically constant in price during the past fifteen years. 
In this period not only have wide fluctuations occurred 
in prices of nitrogen and phosphoric acid from the 
different sources, but they are much lower now than 
formerly. 

The Importance of Potash as a Constituent of 

Fertilizers 

It has been attested that potash is of relatively less 
importance than either nitrogen or phosphoric acid, 
inasmuch as good soils are naturally richer in this 
element, and because a less amount is removed in 
general farming than of either nitrogen or phosphoric 
acid, as the potash is located to a less extent in the 
grain than in the straw, which is retained upon the 
farm. It is, however, a very necessary constituent of 



FORMS OF POTASH 93 

fertilizers, being absolutely essential for those intended 
for light, sandy soils and for peaty meadow lands, as 
well as for certain potash -consuming crops, as potatoes, 
tobacco and roots, since these soils are very deficient 
in this element, and the plants mentioned require it in 
larger proportion than do others. In fact, it is be- 
lieved by many careful observers, — and the belief has 
been substantiated in large part by experiments already 
conducted, — that the average commercial fertilizer does 
not contain a sufficient amount of this element. It is 
a particularly useful constituent element in the building 
up of worn-out soils, because contributing materially 
to the growth of the nitrogen -gathering legumes, an 
important crop for this particular purpose. 

Forms of Potash 

Potash, as has already been stated in the discussion 
of phosphoric acid and nitrogen, exists in various 
forms, but it differs from the other elements in that 
its chemical form or combination seems to exert but 
relatively little influence upon the availability of the 
constituent. For example, it may be in the form of 
a muriate or chlorid, of a sulfate or of a carbonate, 
and while there is a difference in the diffusibility of 
these different compounds, — that is, a difference in the 
rate rat which they will distribute in the soil before 
becoming fixed, — there seems to be very little dif- 
ference in the rate of the absorption of the potash 
by the plant. Nevertheless, the form of potash must 
be observed, because of the possible influence that the 



94 FERTILIZERS 

substances with which it combines may exert in 
reducing the marketable quality of the crop to which 
it is applied. This influence has been very distinctly 
observed, particularly in the growing of tobacco, sugar- 
beets and potatoes, and it has been shown that the 
potash in the form of a chlorid (or muriate) does exert 
a very deleterious effect, especially on tobacco. In fact, 
tobacco manures should not contain potash in the 
form of a muriate. For such crops as the various 
clovers, Indian corn (maize), and the various grasses, no 
particular difference has been observed, and the form 
of potash that may be procured at the lowest price 
per pound of the constituent is the one, other things 
being equal, to use for these crops. 

Kainit 

In the next place, the potash salts that may be 
obtained are divided into two classes ; first, the crude 
products of the mines, and second, the manufactured 
products. Of the crude products, kainit is the one 
more largely used in this country than any other. 
The potash contained in it is practically all in the 
form of a sulfate, though its effect is the same as if 
it were in the form of a muriate, because of the large 
quantities of other salts, chiefly sodium chlorid, or 
ordinary salt, and magnesium chlorid, with which the 
sulfate of potash is associated. It contains on the 
average 12.5 per cent of actual potash, or equivalent 
to about 23 per cent of sulfate of potash and 33 per 
cent of ordinary salt, and smaller percentages of 



CRUDE POTASH SALTS 95 

magnesium chlorid and magnesium sulfate. Because 
of its low content of potash as compared with the 
manufactured products, the cost of the actual potash 
is usually greater than in these, owing to the in- 
creased cost of shipping and handling per unit of 
potash. It is more generally used near the sources 
of supply, rather than at a distance, unless the sub- 
stances, as ordinary salt, also exert a beneficial indirect 
influence upon the soil, as is very frequently the 
case. It is not advisable to apply it immediately 
preceding the planting, nor in the hill or row, because 
of the danger to the young plant from the excess of 
both the chlorids of sodium and magnesium, which 
are injurious to the tender rootlets. Where its use is 
intended to benefit the immediate crop, it should be 
applied a considerable time before the crop is planted, 
in order that it may be well distributed, and that a 
portion of the chlorids, which are extremely soluble, 
may be washed into the lower layers, or into the 
drains. 

Sylvinit 

Sylvinit is somewhat similar to kainit in composi- 
tion, in that it does not contain a large amount of 
actual potash, and the potash is associated with other 
substances, as sodium and magnesium chlorids, though 
less than is the case with kainit. The potash in the 
sylvinit, however, exists both in the form of a sulfate 
and of a chlorid. It is not as largely exported to 
this country as the kainit, and contains on the average 



96 FERTILIZERS 

about 16 per cent of actual potash. Its effect as an 
indirect manure is very similar to that of kainit, 
the salts associated with the potash having a beneficent 
effect in dissolving and making other substances in 
the soil available to the plant, particularly phosphates, 
as well as aiding in the improvement of the physical 
character of soils. 

Muriate of Potash 

Of the manufactured products, the muriate (chlorid) 
of potash is more generally used than any of the 
others. It varies somewhat in composition, accord- 
ing to the method of manufacture, though prac- 
tically only three grades are offered. That most 
commonly met with in this country contains about 
50 per cent of actual potash, equivalent to 80 per 
cent muriate. The chief impurities are common salt, 
or sodium chlorid, and insoluble matter, which are not 
deleterious substances. The lower the content of 
potash the higher the content of impurities, though 
in all cases this form of potash is sold upon the basis 
of 80 per cent muriate. 

Recently a Scotch kiln -dried muriate of potash has 
been offered, which is much richer in actual potash 
than the other grades, containing over 98 per cent of 
pure muriate. The chief advantage of this higher 
grade is that the cost of handling per unit of actual 
potash is reduced, a point of considerable importance 
at points distant from sources of supply. The actual 
potash is no better than in the lower grades. 



EIGH-GBADE POTASH SALTS 97 

High-grade Sulfate of Potash 

High-grade sulfate of potash is usually sold on a 
purity basis of 98 per cent, or an equivalent of 53 per 
cent actual potash. It naturally varies somewhat in 
its composition, owing to possible impurities, either 
introduced or imperfectly removed. It is, however, 
regarded as preferable to the muriate for some crops, 
for the reasons already given (page 94), though until 
recent years it has been much more expensive, and 
thus not so largely used by the manufacturers of 
fertilizers. It is rather less diffusible than the muri- 
ate, though it is not believed to be inferior to it as a 
source of actual potash. 

Double Sulfate of Potash and Magnesia 

This is a lower grade in its content of potash, 
though similar to the high grade in its effect, as it 
contains no deleterious substances, and in many cases 
the sulfate of magnesia with which it is associated is 
believed to be of considerable service. The potash 
contained in it is equivalent to about 26 per cent of 
actual potash, though lower grades are made. These 
are known under the name of double -manure salts. 
The cost of the actual potash in the double sulfate is 
also greater than in the muriate. 

Upon standing, all of the potash salts have a ten- 
dency to become hard, though, with the exception of 
kainit, they are easily pulverized, and thus readily 
distributed, either broadcast or in driUs. 



98 FERTILIZERS 

Fixation of Potash 

Potash, like phosphoric acid, is readily fixed in the 
soil, though the chlorids with which it is combined 
when applied may form soluble compounds that are 
readily leached from the soil. For example, the 
chlorin combined with the muriate may be combined 
with lime or soda, forming soluble chlorids of lime or 
soda ; hence, heavy applications of muriate of potash 
may result in the exhaustion of lime in the soil. The 
fact that the potash is fixed, and that the chlorids 
remain soluble, enables the application of a large 
quantity, which might otherwise be injurious. That 
is, if muriate of potash is applied a considerable 
time before the crop that may be injui-ed by excess 
of chlorids is planted, the chlorids are washed out, 
while the potash remains. 

Another point of importance should be observed in 
this connection: the rapidity of fixation on many soils, 
especially those of an alluvial character, which ex- 
plains the recommendations frequently made to apply 
potash salts broadcast and immediately cultivate in, 
otherwise the fixation would take place at points of 
contact, and the distribution be incomplete. 



CHAPTER VI 

MISCELLANEOUS FERTILIZING MATERIALS 

In addition to the specific fertilizer materials de- 
scribed in the previous chapters, which constitute the 
standard sources of supply, a number of other pro- 
ducts exist, and should be considered here. Certain 
of these maj'' serve in the manufacture of fertilizers, 
and certain others, which are not suitable for this pur- 
pose, may be used to advantage either because they 
furnish the constituents in considerable quantities, or 
in other ways assist in improving the fertility of the 
soil. They are often a cheap source of nitrogen, 
phosphoric acid or potash, besides contributing toward 
"condition" of soil, which exercises a decided influ- 
ence in making possible the best use of commercial 
fertilizers. 

Furthermore, while a consideration of these products 
may not be regarded as strictly pertaining to the sub- 
ject of commercial fertilizers, a discussion of them is 
valuable, in order that certain impressions now existing 
concerning them may be corrected. These impressions, 
while not entirely erroneous, are not wholly in accord 
with scientific facts, particularly as to how far they 
may substitute the better products; and on this point 
information as full and exact should be had as the 
limited knowledge that we have of the subject will 

(99) 



100 FERTILIZERS 

permit. These various products cannot be strictly 
classified into the three main groups : nitrogenous, 
phosphatic and potassic. They are, as a rule, rather 
general in their ejffect ; they contain small amounts 
of all the essential constituents rather than large 
amounts of one or two, and many of them are useful, 
practically altogether because of their indirect action. 

TOBACCO STEMS AND STALKS 

Tobacco stems consist of the waste stems or ribs 
of the leaves, and parts of the leaves themselves, 
which result from the stripping of tobacco for the 
manufacture of cigars, or for smoking and chewing 
tobacco. The stalks include the main stem and 
branches of the plant. The stems are frequently 
ground and sold as a fertilizer, and the product is 
chiefly valuable for its nitrogen and potash — the 
nitrogen ranging in content from 2 to 3 per cent 
and the potash from 6 to 10 per cent. They contain 
but small amounts of phosphoric acid. The nitrogen 
exists in both the nitrate and organic forms. The 
nitrate form constitutes from one -third to one- 
half of the total nitrogen, and its presence is due 
both to the fact that nitrogen exists as such in the 
tobacco plant, and to the fact that saltpetre (nitrate 
of potash) is frequently added in order to improve 
the marketable quality of the lower grades of 



Note. — Full discussions of stable manures are contained in Roberts' 
"Fertility of the Land;" and that book also has a table of compositions 
of very many materials which are used for fertilizing the land. 



TOBACCO STEMS 101 

tobacco. The potash occurs largely in the soluble 
form, and is free from chlorids. The tobacco stalks 
are somewhat richer in nitrogen than the stems, 
ranging from 3 to 4 per cent, and are poorer in pot- 
ash — about 4 to 5 per cent of potash — though the 
forms of these two constituents are similar in the 
case of both to those contained in the stems. Both 
stems and stalks may be frequently obtained in the 
vicinity of towns where tobacco manufacture is carried 
on, and while more variable in their content of nitro- 
gen and potash than the ground stems and stalks, 
due largely to the variations in the content of mois- 
ture, they are a useful and often a very cheap source 
of nitrogen and potash. 

These waste tobacco products are free from dele- 
terious compounds, and for this reason alone are 
highly valued as a fertilizer for tobacco, as well as 
for small fruits, for which they are especially useful, 
because of their known insecticidal value. A ton of 
tobacco stems of good quality contains nitrogen equiv- 
alent to the amount contained in 500 pounds of ni- 
trate of soda, and potash equivalent to the amount 
contained in 200 pounds of high-grade sulfate of 
potash. They, therefore, possess a distinct value as 
a source of these constituents. 

CRUDE FISH SCRAP 

It frequently happens that farmers are so situated 
as to be able to procure directly from the fishermen 
the fish scrap from which dried ground fish is made. 



102 PEBTILIZEBS 

Very large amounts are used in this crude form in 
our coast states, particularly New England and the 
middle states. This material, while chiefly valuable 
for its nitrogen, is not uniform in its content of fer- 
tilizing constituents, owing to the wide variation in 
the content of moisture, or water, which may range 
from as low as 25 to as high as 75 per cent. The 
nitrogen, of course, varies with the dry matter, and 
ranges from 2.5 to 8 per cent. The scrap also con- 
tains considerable amounts of phosphoric acid, ranging 
from 2 to 6 per cent. The fish scrap in this form, 
too, is less valuable as a source of nitrogen than the 
dried ground material, because of its coarser condi- 
tion, requiring a longer time for decay. 

The whole fishes (menhaden) are also used either 
directly or in a composted form in many instances, 
and the excellent results obtained are mainly due to 
the rapidity of decay of the nitrogenous substances. 
The economical purchase of these products depends 
largely upon the judgment of the farmer. He should 
be guided in determining their value by the amount 
of water contained in them. As they approach dry- 
ness, they become richer in the constituents of fer- 
tility. In any case, products of this sort should be 
obtained at so low a price per ton as to guarantee to 
the purchaser a maximum quantity of the fertilizing 
constituents for his money, when measured by the 
market value of the materials of known composition. 

For example, if crude fish scrap, which contains 
as a minimum 2.5 per cent of nitrogen, can be pur- 
chased for $5 per ton, it will furnish nitrogen at 10 



WOOL AND HAIR WASTE 103 

cents per pound, or at two -thirds the cost of this 
element in nitrate of soda at $48 per ton. Besides, 
the scrap contains phosphoric acid in good forms. At 
this price, the purchaser could afford to take the risk 
incident to the variability of the product. 

WOOL AND HAIR WASTE 

Wool and hair waste have already been described 
in part, though more largely from the manufacturers' 
standpoint, as representing materials that may be 
utilized in the manufacture of commercial fertilizers. 
These products may frequently be obtained in large 
quantities and at a low price per ton in towns in which 
the original products are used in manufacturing, and 
thus occur as wastes. Both are extremely variable in 
their composition, the wool, particularly, being very 
liable to change in this respect, owing both to the 
admixture of non- nitrogenous substances, such as 
cotton, and to the source of the waste itself, 
whether it consists of the clippings and tags from the 
original fleece, or whether it is in part the manu- 
factured product. Different samples show a wide range 
in the content of nitrogen and potash, from 2 to 10 
per cent in the former, and from 1 to 3 per cent in 
the latter. The nitrogen in the waste is extremely 
slow in its action in the soil, though it may be made 
directly useful, both as an absorbent of other wastes, 
as in liquid manure, and as an ingredient of com- 
posts. Excessive quantities must be applied in order 
to obtain a marked Immediate result. 



104 FERTILIZERS 

The hair waste is also variable, both on account of 
the content of moisture, as well as the admixture with 
it of other substances. 

Lime often occurs as a waste product in some 
industries, and as such it is frequently wet and pasty, 
and not easily handled. 

These wastes, when they can be purchased at a low 
price per ton, — and frequently they may be obtained 
as low as two or three dollars, — serve an excellent 
purpose as absorbents, and for use in orchards and 
pastures, or in gradually building up the fertility of 
poor soils. 

POULTRY AND PIGEON MANURES 

These products accumulate in considerable amounts 
on many farms, and are often more highly valued 
than their composition warrants. Many believe that 
they can be favorably compared with high-grade com- 
mercial fertilizers. The good results obtained are 
doubtless due to the readily available form in which 
the nitrogen exists, since the examination of these 
products does not show them to be particularly rich 
in nitrogen, or in the mineral elements of fertility, 
phosphoric acid and potash. 

Chicken manure in the fresh state contains from 
50 to 60 per cent of water, from 1 to 1.5 per cent of 
nitrogen, and about .50 to .75 each of phosphoric acid 
and potash. When brought to the air -dry state, — that 
is, if allowed to thoroughly dry in the air,— it contains 
from 10 to 20 per cent of water, and the content of 



SEWAGi; 105 

the fertilizing constituents is about doubled. Thus, 
even in the best condition, these products compare 
favorably with commercial fertilizers only in their 
content of nitrogen. Naturally they also vary in 
their composition, according to the character of food 
used in their production. 

Pigeon manure differs but little from hen manure 
in composition, though usually it is much drier and 
somewhat richer in nitrogen. 

These products should be cared for, since the con- 
stituents in them serve quite as well in the feeding 
of plants as those contained in the more concentrated 
forms, though a higher estimation should not be placed 
upon the constituents than upon those contained in 
commercial forms which are quite as good. 

SEWAGE 

In recent years, great progress has been made in 
the handling of sewage from cities, and there is now 
a product called "sewage sludge," which is obtained 
in many towns, as a result of its chemical treatment. 
Such examinations as have been made of this product 
show it to be very poor in the fertilizing constituents, 
showing less than .20 per cent nitrogen, .05 phosphoric 
acid, and .05 potash. It is seldom worth the handling. 
The untreated sewage and garbage wastes are also 
obtainable in large quantities, and while the con- 
stituents contained in them act quickly, and while 
they are considerably richer in these than the sludge 
wastes, it seldom pays the farmer to handle them, 



106 FERTILIZERS 

owing to their offensive character and the enormous 
amount of useless moisture contained in them. 



MUCK AND PEAT 

"On many farms there are low, wet places, where 
the conditions are favorable for the collection of 
partially decayed vegetable matter. The material thus 
formed is called muck or peat. The thickness of the 
deposit, and its character, depend upon the time during 
which it has been formed, and the character of the 
climate." * 

Muck is used mainly as a source of humus, and 
serves an excellent purpose as an absorbent in 
cattle stalls or yards. Fresh muck, while varying in 
composition according to its source, may be said to 
contain on the average 75 per cent of water and 
about .75 per cent of nitrogen, and only traces of 
potash, phosphoric acid and lime. Air-dry muck also 
varies in composition, largely owing to the different 
proportions of vegetable and mineral matter contained 
in the different products, as well as the amount of 
water absorbed in its dry state. The richer it is in 
vegetable dry matter, the richer in nitrogen. The 
value of the muck as a source of humus is measured 
by its content of nitrogen, while its value as an ab- 
sorbent depends upon its content of organic matter. 
The value of muck for either of these purposes is 
further modified by the labor necessary to secure it in 



* Voorhees, "First Principles of Agriculture." 



KING CBAB— MUSSELS 107 

a dried coudition. This product is of doubtful value 
as a source of immediately available nitrogen. 

"The usual method of securing it is to throw it 
out of the bed into heaps, and allow it to dry before 
it is used, either upon the field or in the stables. 
Where a muck bed exists upon a farm, it should first 
be studied in reference to its possible drainage. If it 
can be drained, it is liable to prove more useful where 
it lies than for the other purposes mentioned." * 



KING CRAB, MUSSELS AND LOBSTER SHELLS 

King crab, already described in the discussion of 
nitrogenous fertilizing materials (page 43), is also 
used in many sections of New Jersey in its green or 
fresh state, either directly on the land or in the form 
of a compost, and because of its nitrogenous charac- 
ter, and its tendency to rapid decay, is a valuable 
source of this element, of which, in its fresh state, it 
contains from 2 to 2.5 per cent. 

In certain sections of the coast states farmers have 
access to an almost unlimited supply of mussels, which 
may be had for the carting. Analyses made at the 
New Jersey Experiment Station show them to contain, 
in their natural state, a very considerable amount of 
fertilizing constituents, the nitrogen reaching .90 per 
cent, the phosphoric acid and potash .12 and .13 per 
cent, respectively, and the lime 15.84 per cent. 
The organic portions of the mussels decay rapidly, 



• "First Principles of Agriculture." 



108 FERTILIZERS 

and serve as a fairly good source of nitrogen ; and 
since this product is twice as rich in this constituent 
as average yard manure, it is well worth the expense 
of handling. 

Lobster shells are also a waste of considerable im- 
portance, since they can be obtained at a very low cost, 
often for the carting. They contain, in their di-y state, 
an average of over 4 per cent of nitrogen, 3 per cent 
of phosphoric acid, and about 20 per cent of lime. 

These products, of course, are not to be depended 
upon for the entire supply of constituents to crops ; 
they are mainly useful in improving the natural quality 
of the soil by building it up in vegetable matter con- 
taining nitrogen. Their best use requires the addition 
of the minerals from other sources. 



SEAWEED 

In the coast states, seaweed is held in high esteem 
as a manurial product. In Connecticut, Rhode Island 
and New Jersey, the use of seaweed as a fertilizer is 
very general. In Rhode Island the annual value of the 
manure from this source has been estimated to be as 
high as $65,000.* 

In its fresh state it contains from 70 to over 80 per 
cent of water, and is thus economically used in that 
condition only near the shore. It is frequently spread 
out in thin layers and dried, in which condition it can 
be profitably transported considerable distances. 



* Bulletin 21, Rhode Island Experiment Station. 



WOOD ASHES 109 

Seaweeds of different kinds differ in their content 
of the fertilizing constituents. Certain of them show 
a relatively high content of nitrogen, and others of 
potash, and they furnish more of these constituents 
than of phosphoric acid. All seaweeds contain con- 
siderable salt, though if they are not used in too large 
quantitie?, no serious injury is liable to follow. In 
fact, salt in some instances is a substance of con- 
siderable indirect manurial value. Seaweed manure 
is certainly worthy of consideration where it can be 
obtained in quantity for the expense of carting. 

WOOD ASHES AND TAN -BARK ASHES 

Wood ashes contain potash in one of the best forms, 
and were, in the early history of manuring, practi- 
cally the only semi -artificial source of this element. 
At the present time, however, the supply is limited, 
and the average content of potash in the commercial 
article is much lower than was formerly the case. 

The pure ash is not a uniform product. That from 
the different varieties of wood varies in composition. 
As a rule, the softer woods are poorer and the hard 
woods richer in potash than the average, the range 
being from 16 to 40 per cent. 

"Ashes also contain lime in large quantities, while 
phosphoric acid is contained in much smaller quanti- 
ties. Wood ashes, as usually gathered for market, 
however, contain very considerable proportions of mois- 
ture, dirt, etc., which cause a variability in composition 
not due to the character of the woods from which they 



110 FERTILIZERS 

are derived. The average analysis of commercial wood 
ashes shows them to contain less than 6 per cent of 
potash, 2 of phosphoric acid and 32 per cent of lime. 
Leached wood ashes contain on the average 30 per cent 
of moisture, 1.10 of potash, 1.50 of phosphoric acid 
and 29 per cent of lime. 

"Ashes are probably one of the best sources of 
potash that we have, so far as its form and combina- 
tion are concerned, being in a very fine state of divi- 
sion, and in such a form as to be immediately available 
to plants. Ashes also have a very favorable physical 
effect upon soils, the lime present, of course, aiding in 
this respect. Canada is now the main source of wood 
ashes, the substitution of coal for wood making the 
supply in this country for commercial purposes very 
limited. Owing to the variability of this product, it 
should always be bought subject to analysis, and to a 
definite price per pound for the actual constituents 
contained in it, which should not be greater than the 
price at which the same constituents could be pur- 
chased in other quickly available forms." * 

Tan -bark ashes are much poorer in fertilizing 
content than those obtained from the regular com- 
mercial sources of supply. They seldom contain more 
than 2 per cent of potash, 1.5 per cent of phosphoric 
acid and 33 per cent of lime. 

Lime -kiln ashes are obtained in the burning of 
lime with wood, and are also relatively poor in potash, 
containing less than 1.5 per cent of potash and 1 per 

•"First Principles of Agriculture." 



COAL AND COTTON -HULL ASHES HI 

cent of phosphoric acid. The product is, however, 
much richer in lime than the average wood ashes, often 
containing as high as 50 per cent of calcium oxide. 

COAL ASHES 

It is believed by many that coal ashes, because of 
their favorable effect upon many soils, also possess 
considerable fertilizing value, whereas analyses show 
them to contain only traces of soluble potash and of 
phosphoric acid. The good results from their use is 
undoubtedly due to their beneficial indirect effect in 
improving the physical character of heavy soils. 



COTTON -HULL ASHES 

Cotton -hull ashes were formerly made in consid- 
erable quantities in the southern states, where the 
hulls were used as fuel in the furnaces connected with 
gins and presses. This product, while exceedingly 
variable in composition, is usually very rich in potash, 
besides containing a very considerable amount of 
available phosphoric acid. A large number of samples 
have been examined at the Connecticut Experiment 
Station,* and the results of the study show that no 
average percentage composition is a suflBcient guide 
as to their quality. They can be safely purchased 
only on the basis of their actual composition. They 
are an excellent source of potash and phosphoric acid. 



•Annual Report for 1897 (Part II.), Connecticut Experiment Station. 



112 FERTILIZERS 

because free from chlorids and other deleterious sub- 
stances, but are not so rich in lime. They are espe- 
cially useful for such crops as are injured by the 
presence of chlorids. 

MARL* 

Marl may contain one or more of the constituents, 
phosphoric acid, potash and lime. Shell marls are 
usually very rich in lime, but contain only .traces of 
phosphoric acid and potash. The green sand marls of 
New Jersey often contain very considerable amounts 
of phosphoric acid and potash, though they vary 
widely in composition. They contain, on the average, 
2.20 per cent of phosphoric acid, 4.70 per cent of 
potash, and 2.90 per cent of lime. These constituents, 
particularly the potash, are, as a rule, slowly available. 

Marl, however, is an important amendment to soils, 
not only because of its content of mineral constituents, 
but because these constituents are associated with 
products that exert a very favorable mechanical effect 
upon soils. Large areas of land in the state of New 
Jersej^ formerly unproductive, chiefly because of phy- 
sical imperfections, have been made very productive 
mainly through the application of marl. 

The use of marl is now less general than when the 
fertilizing constituents from artificial sources were 
dearer, and when the labor of the farm was more 
abundant and cheaper. The quicker effect of more 
soluble fertilizer constituents has had an influence in 

*" First Principles of Aci"i<!ulture." 



LIME 113 

reducing the use of marl where quick returns are 
desirable. Where farmers have deposits of marl upon 
their own farms, or within short distances of them, 
and can secure it at a low price per ton, its ap- 
plication is a desirable method of improving land. 

The results from the use of marl are frequentlj'' due 
quite as much to the improvement given to the phy- 
sical condition of soils as to the increase in fertility 
furnished by the essential mineral constituents. Marl 
may be carted and spread upon the land when other 
work of the farm is not pressing, thus making it 
possible to get a considerable addition of fertility at a 
small expense. 

LIME 

"Lime, as it is generally known, is an oxide of 
calcium, and is produced by burning limestone, or 
carbonate of lime. The lime loses the carbonic acid 
when burned in the kilns, and the oxide of lime 
remains behind; this is termed 'burned lime,' 'quick- 
lime,' or 'stone lime,' and is usually slaked before 
it is applied to the soil. This is done by adding 
water, which the lime absorbs, and falls to a powder. 
Slaked lime, also called caustic lime, is a calcium 
hydrate. 

"The more completely limestone is burned, the 
better the quicklime, and the more completely it 
slakes. We have, when we speak of lime, three 
forms: limestone, quicklime and slaked lime, each dif- 
fering from the other in composition. 



114 FERTILIZERS 

"Quicklime absorbs moisture, and slakes when 
exposed to the atmosphere. Lime thus slaked is 
called 'air-slaked lime,' and is usually less com- 
pletely changed to a hydrate than when water is 
added. Quicklime also absorbs carbonic acid from 
the air, and changes back to the limestone form. 
Lime in the carbonated form, if finely pulverized, is 
better for liming light lands than the caustic lime, 
while for heavy lands, the caustic is preferable to 
the carbonate." * 

What is termed "marble lime" is made from pure 
limestone, and the burned lime thus obtained is prac- 
tically pure oxide of lime. Limestone, so called, is 
not always pure. It is a mixture of lime and mag- 
nesia, in which case it is the mineral "dolomite," and 
is termed "magnesian limestone." A very large 
quantity of the lime used in the eastern states is the 
magnesian form. The burned lime from the magne- 
sian limestone contains from 50 to 60 per cent of 
calcium oxide, and 30 per cent or over of magnesium 
oxide. Li some instances, the magnesia is of value, 
though it is rather inert in its effect, and is less use- 
ful than the lime. A safe rule in the purchase and 
use of lime is to adjust the price to the proportionate 
percentage of actual lime present, or practically in 
the ratio of 10 to 7. 

Oyster shells are nearly pure carbonate of lime, 
and oyster shell lime, while practically pure lime, so 
far as this element is concerned, is usually mixed with 

*" First Principles of Agriculture." 



GAS LIME AND GTPSUM 115 

more or less dirt and other impurities, and is, there- 
fore, not as rich in lime as that derived from pure 
limestone. 

"Gas lime is also frequently used as manure ; in 
gas works, quicklime is used for removing the impuri- 
ties from the gas. Gas lime, therefore, varies con- 
siderably in composition, and consists really of a mix- 
ture of slaked lime, or calcium hydrate, and carbo- 
nate of lime, together with sulfites and sulfides of lime. 
These last are injurious to young plant life, and gas 
lime should be applied long before the crop is planted, 
or at least exposed to the air some time before its 
application. The action of air converts the poisonous 
substances in it into non- injurious products. Gas 
lime contains on an average 40 per cent of calcium 
oxide, and usually a small percentage of nitrogen."* 

Where it can be used to advantage, its cost should, 
as in the case of the other, be based on the proportion 
of actual lime present. 

Gypsum is a sulfate of lime, containing water in 
combination. Pure gypsum contains 32.5 per cent of 
lime, 46.5 per cent of sulfuric acid, and 21 per cent 
of water. 

Plaster of Paris is prepared from gypsum by burn- 
ing, which drives off the water it contains. 

Gypsum, like other forms Of lime, furnishes directly 
the element calcium, and also exerts a favorable solvent 
effect upon the soil. It was formerly used in large 
quantities, particularly for clover, and it is believed 



•"First Principles of Agriculture." 



116 FERTILIZERS 

that its favorable effect was due, not so much to the 
direct addition of lime, as to its action upon insoluble 
potash compounds in the soil, in setting free potash. 
Thus the application of plaster caused an increase in 
crop, because of the potash made available. 

We have in the eastern states two main sources 
of gypsum, namely, Nova Scotia and Cayuga, N. Y. 
Nova Scotia plaster contains on the average over 
90 per cent of sulfate of lime, and is, therefore, 
purer than that obtained from Cayuga, which often 
shows as low as 65 per cent of pure sulfate; the 
latter, however, frequently contains appreciable amounts 
of phosphoric acid. 

In many places it is possible to obtain plaster 
which is a waste in the manufacture of phosphorus. 
This waste contains the plaster in a precipitated form, 
and frequently also contains considerable amounts of 
phosphoric acid. The disadvantage of this waste lies 
in the fact that it is frequently wet and lumpy, and 
thus not easily handled and distributed. Its advan- 
tage lies in its content of phosphoric acid, which 
ranges from 1.5 to 2 per cent, though as a rule, it can 
be purchased at a lower price per ton than that from 
the regular sources. 

AGRICULTURAL SALT 

Agricultural salt, which is chiefly common salt, is 
also frequently used as a manure. "It supplies no 
essential plant -food constituents, and its value is still 
a disputed point, though it is admitted that where its 



SALT AND POWDER WASTE 117 

use is favorable, it is due to indirect action in aiding 
the decomposition of animal and vegetable matter, 
increasing the absorbing power of soils, and, by its 
reaction with lime, acting as a solvent for phosphates."* 
There would seem to be no good reason for paying 
from $4 to $6 per ton for this substance, when prac- 
tically the same effect can be obtained from the salt 
contained in the crude potash salt, kainit, one -third 
of the total weight of which is common salt. This, 
too, may be had free of charge, or for the handling, 
as the market price of the kainit is based upon its 
content of potash. 

POWDER WASTE 

Powder waste also consists largely of common salt, 
though frequently containing appreciable percentages 
of nitrogen in the form of a nitrate. Its use can 
only be recommended when it can be obtained at a 
low price per ton, or for the handling, and upon soils 
that show a marked benefit from its application. 

GREEN MANL'RES 

A great deal of misconception is prevalent con- 
cerning the value of what are termed "green manures." 
These do possess a distinct value, and a proper under- 
standing of their place in farm management will 
undoubtedly result in their larger and better use, and 

* " First Principles of Agriooltuie." 



118 FERTILIZERS 

in the consequent improvement of agricultural prac- 
tice. By green manures is meant any crop that is 
grown primarily for the purpose of improving the 
soil, and not for the harvested product, 

^^ Nitrogen Gatherers ^^ mid ^^ Nitrogen Consumers ^^ 

In this sense any crop will serve as a green 
manure, yet certain crops possess a greater value than 
others for this purpose, because they are able to obtain 
certain of their constituents from sources not acces- 
sible to all crops. In other words, the one class of 
plants can obtain the nitrogen necessary for their 
growth from the air, as well as from the soil; the 
other, as far as we now know, can obtain it only 
from the soil. These two groups of plants are, there- 
fore, classified as "nitrogen gatherers" and "nitrogen 
consumers." 

The nitrogen gatherers belong to the legume, or 
clover family, and do not depend solely upon soil 
sources, but rather gather the element from outside, 
and thus do not reduce the content of soil nitrogen. 
Distinguishing features of the plants of this order 
are that the seeds are formed in a pod or legume, and 
that they have the power of acquiring at least a large 
part of their nitrogen from the air. These, when 
plowed down as green manures, add directly to the 
crop -producing capacity of soils poor in nitrogen, 
because increasing their content of this element. In 
order that the plant may obtain its nitrogen from 
the air, however, the soil must originally contain, or 



THU ADVANTAGES OP GEE EN MANURES 119 

must be inoculated with, a specific germ, the presence 
of which is manifested by the growth of nodules 
upon the roots, through which it is believed the 
nitrogen is obtained. Most well -tilled soils contain 
these germs in abundance. 

The "nitrogen consumers" are those which can 
obtain their nitrogen only from the soil ; these con- 
sume the nitrogen existing there, and their growth 
and removal exhausts the soil of this element. 

Notwithstanding the very great advantages of the 
"nitrogen gatherers" as green manures, they cannot 
be solely depended upon to increase the crop -produc- 
ing capacity of the soil. That is, soils that are very 
poor, both in their content of nitrogen and of the 
essential mineral elements, cannot be made very pro- 
ductive by the sole use of green manures. In fact, 
the green manure crops cannot be grown with ad- 
vantage unless they are supplied with an abundance 
of the mineral elements, phosphoric acid and potash ; 
hence helpful green manuring for such soils must be 
preceded and accompanied by liberal fertilization with 
the minerals, phosphoric acid, potash and lime. With 
these added in sufficient amounts, and with the specific 
bacteria present in the soil, their use results not only 
in the addition of nitrogen to the soil, which may] be 
useful for other plants, but by the accumulation of 
vegetable matter, which improves the physical char- 
acter, usually imperfect in this class of soils. The 
nitrogen thus introduced into the soil is also in a very 
good form; that is, it has a tendency to decay rap- 
idly and thus supply the needs of other plants, but 



120 FERTILIZERS 

the helpful additions to the soil are limited to organic 
matter and nitrogen. The mineral constituents ab- 
sorbed by the crop may be more available for other 
crops, but they formerly existed there. No additions 
of these are made by the growing of the crop ; hence 
no system of green manuring can be made successful 
unless^chere is a previous abundance in the soil of the 
mineral elements, or unless these have been directly 
applied. 

The Most Useful Crops 

Of the crops most useful for green manures, red 
clover, crimson clover, cow peas and soja beans are 
first in order ; first, because of their capacity to 
gather nitrogen, and second, because of their period 
and time of growth. Whether these plants will 
gather all of the nitrogen of their growth from the 
air, other conditions being good, depends upon 
whether the soil is rich or poor in nitrogen, since it 
has been shown that these plants will gather at least 
a part of the nitrogen from the soil in preference to 
that from the air, unless they are starved in respect 
to soil nitrogen. The amounts that may be gathered 
from the air, therefore, are not measured by the total 
content of nitrogen contained in the plant grown 
(which may, in the case of good crops, amount to as 
much as 200 pounds per acre, sufficient for the use of 
several good crops of wheat, or other cereal grains), 
but apparently by the poverty of the soil in this ele- 
ment. The fact that an accumulation of nitrogen 
does occur has been distinctly shown, and their con- 



CROPS USEFUL AS ORE EN MANURES 121 

tinuous growth, therefore, would have a tendency to 
over -enrich the soil in this constituent, unless accom- 
panied by an abundant supply of minerals, particu- 
larly in the improvement of light lands and in 
orchards and vineyards, for which their right use 
is very beneficial. 

Experiments conducted in this as well as other 
countries, show that the nitrogen so gathered and 
stored in the soil may be readily obtained by cereal 
and other nitrogen -consuming crops. In experiments 
conducted by the New Jersey Experiment Station, on 
a poor, sandy soil, in which the mineral elements, 
phosphoric acid, potash and lime, only, were added, 
a crop of cow peas gathered, in the roots and tops, 
75 pounds of nitrogen, equivalent to that contained 
in 470 pounds of nitrate of soda, which when turned 
under was capable of feeding a rye crop with suf- 
ficient nitrogen to produce a most excellent crop, 
quite as good as that grown on land long under cul- 
tivation and well -manured. Further experiments con- 
ducted with crimson clover* show that the nitrogen 
gathered was capable of supplying the needs of fruit 
trees quite as well as when the nitrogen was applied 
in the immediately available form contained in nitrate 
of soda. 

If it were necessary to do so, numerous experi- 
ments might be cited to show that the nitrogen is 
gathered from the air by these plants, and that it is 
capable of providing that required for those other 
crops which can obtain it only from the soil. 

* AhuuaI Report for 1864, N«w Jersey Ezperimeiit SUtioa. 



122 FERTILIZERS 

Oreen Manure Crops that Consume the Nitrogen 
in the Soil 

In addition to the legumes, other crops are used 
as green manures, chief of which are rye, buckwheat 
and mustard, not because they are capable of directly 
gathering nitrogen, but because their period and time 
of growth are such as frequently to enable them to 
serve a very useful purpose in preventing losses in 
fertility. In the growth of these crops, however, the 
only real addition to the soil is the amount of non- 
nitrogenous organic matter contained in them. The 
nitrogen gathered is in direct proportion to the 
amount contained in the soil and the relative feeding 
capacity of the plant. The nitrogen is not obtained 
from the atmosphere, and the soil has not accumu- 
lated nitrogen by virtue of their growth, and is not 
richer in this element, except in so far as by their 
growth they prevent the escape of readily available 
nitrogen into the drainage waters. The nitrogen 
gathered is "soil nitrogen," and its conversion into a 
crop simply results in changing its form and place. 
The specific use of these crops, therefore, so far as 
directly contributing to the fertility of the soil is con- 
cerned, is to prevent the possible loss of nitrogen and 
other constituents by leaching, which is more liable 
to occur on uncropped soils, though they further 
contribute toward soil improvement by accumulating 
stores of non -nitrogenous vegetable matter. 

These crops, too, in order that they may produce 
largely, must be freely supplied with the mineral ele- 



THE BIGHT USE OF GREEN MANURES 123 

ments, as well as with nitrogen in some form, and 
cannot be regarded as a substitute for the leguminous 
crops, or as a substitute for commercial fertilizers in 
the permanent improvement of the soil, in the sense 
that they actually contribute to its content of fertility 
elements, — an opinion apparently held by many who 
have observed the good results that often follow 
their use. 

Furthermore, these crops contain, as a rule, less 
nitrogen, and besides, that contained in them is 
apparently less available than the nitrogen contained 
in the green manures from the leguminous crops. In 
their growth, too, they appropriate the immediately 
available nitrogen of the soil, and convert it into the 
less available organic form ; hence the crop that fol- 
lows is frequently unable to obtain its food as readily 
as would have been the case, provided the green 
manure crop had not been grown. Therefore, while 
the practice of using green manures is a desirable one 
when properly understood, it should not be regarded 
as a means by which soils may be directly enriched, 
except in the case of the plants of the legume family, 
where nitrogen is really added to the soil. In the 
case of all other crops, the benefit is indirect, and is 
in proportion to the amount of minerals added. 



CHAPTER VII 

PURCHASE OF FERTILIZERS 

Commercial fertilizers, in the form in which they 
are obtained by farmers, are made up of varying pro- 
portions of one or more products from each class of 
fertilizing materials described. That is, every manu- 
facturer is obliged to go to these sources of supply, 
whatever may be the name given to the finished 
product or mixture. Hence the fertilizing materials 
described are not regarded as commercial fertilizers in 
the same light as those which they are able to pur- 
chase under brand names from their local dealers. In 
the first place, a specific fertilizing material, as dis- 
tinct from a manufactured fertilizer, contains, as a 
rule, but one of the essential fertilizing elements, and 
its use under average conditions would be far differ- 
ent from one which contains two or all of the essen- 
tial fertilizing elements. The materials, therefore, 
are classed as nitrogenous, phosphatic and potassic, 
according to whether the material contains nitrogen, 
phosphoric acid or potash as its chief or its only 
constituent element ; and these different classes, too, 
may be again sub -divided into two distinct groups, 
the first including "standard," or high-grade materials, 
and second, "general," or low-grade materials. This 
classification is of the utmost importance. 

(124) 



EIGEGRADE FERTILIZING MATERIALS 125 

STANDARD HIGH-GRADE MATERIALS 

Nitrate of soda, sulfate of ammonia, and dried 
blood are, for example, standard or high-grade 
nitrogenous materials, and belong to the first group. 
They are "standard" because they do not vary widely 
in their composition. A definite quantity can be 
depended upon to furnish not only practically the 
same amount of the specific constituent, but to fur- 
nish it in a distinct and definite form, which is iden- 
tical, from whatever source derived. For example, 
commercial nitrate of soda does not vary materially 
in its composition, and the nitrogen in it is always in 
the form of a nitrate. The same is true of sulfate 
of ammonia. One ton will furnish practically as much 
nitrogen as any other ton, and it is always in the 
form of ammonia. It is also practically true of high- 
grade dried blood. Each lot contains this specific form 
of organic nitrogen, and will always decay at 
practically the same rate, if used under the same 
conditions. They are also high-grade products because 
they are richer in the constituent element, nitrogen, 
than any other, and because this element is im- 
mediately or quickly available. 

The South Carolina, Florida and Tennessee rock 
phosphates differ from the nitrogenous materials men- 
tioned, inasmuch as, in their raw state, they are not 
directly useful as fertilizers, — they are not sources 
of available phosphoric acid. Hence the standard 
supplies of phosphoric acid are derived from these 
materials after they are manufactured into superphos- 



126 FERTILIZERS 

phates. The various kinds of these may be regarded 
as high-grade in the sense that they always possess 
a high content of available phosphoric acid. They 
are standard, too, not only because of this, but 
because they do not vary widely in their composi- 
tion. A definite amount from each class can be de- 
pended upon to furnish practically the same amount 
of available phosphoric acid. For example, a ton of 
South Carolina rock superphosphate, from whatever 
manufacturer obtained, will not vary widely in its 
content of phosphoric acid, and will always act in 
the same waj'' under similar conditions. The various 
German potash salts are also standard and high-grade, 
since the composition of each grade and kind is 
practically uniform in its content of potash, which 
will always act in the same way under the same con- 
ditions, and since they are richer in the specific ele- 
ment, potash, than other potassic compounds suitable 
for the manufacture of fertilizers. 

These various standard, high-grade products, when 
used in the manufacture of fertilizers, make what are 
called "chemical fertilizers," because they are really 
crude chemical compounds, and furnish the particular 
fertilizer elements in their most concentrated and 
active forms. 

FERTILIZING MATERIALS ■WHICH ARE VARIABLE IN 
COMPOSITION 

The products which are included in the second 
group differ from the others, in that they not only 



VARIABILITY OF LOW-OBADE MATERIALS 127 

vary in their content of the specific constituent, or 
in their composition, but they are also variable in the 
sense that the constituents contained in them do not 
show a uniform rate of availability. For example, 
ground bone varies in its composition owing to its 
source and the method of treatment, and the availa- 
bility of the constituents, nitrogen and phosphoric 
acid, also varies because of these conditions, and 
because of its mechanical condition or degree of 
fineness. Different samples of bone derived from the 
same source, treated in the same way, and ground 
to the same degree of fineness, would be regarded as 
standard, but because these conditions differ, bone 
from different sources cannot be depended upon to 
act in the same way under the identical climatic and 
soil conditions. This is also true of tankage, which 
varies, not only in the total amount of the constitu- 
ents contained in it, but in the proportion of its two 
chief constituents, nitrogen and phosphoric acid, and 
in the rate at which they become available to plants. 
In this class belong, in addition to the bone and 
tankage, ground fish, and the various miscellaneous 
products. They cannot be depended upon, either in 
respect to their composition or their availability of 
the essential constituents — important advantages pos- 
sessed by the standard products. 

HIGH-GRADE AND LOW-GRADE FERTILIZERS 

The fertilizers manufactured from these two classes 
of raw materials will, therefore, differ. Those made 



128 FERTILIZERS 

from the first class are always high-grade, both in 
reference to the quality and quantity of the constituents 
that may be contained in a mixture. Those manu- 
factured from the second group are not high-grade, 
so far as the form of the constituent is concerned, 
though they may be high-grade in the sense that they 
contain large amounts of them. In the manufacture 
of fertilizers, too, as a rule, all three of the essential 
constituents are introduced, and the buying of a fer- 
tilizer is really the buying of the three constituents, 
nitrogen, phosphoric acid and potash. Hence, the 
more concentrated the product, or the richer it is in 
these constituents, the less will be the actual cost of 
handling per unit of the constituents desired, and the 
higher the grade of the materials used, the greater 
the proportionate activity of the constituents. 

The " Unit " Basis of Purchase 

In commercial transactions in fertilizing materials, 
two systems of purchase are used. The first is known 
as the "unit" system, in which case the quotations, or 
prices are based on the unit. A unit means one 
per cent on the basis of a ton, or 20 pounds. For 
example, a unit of available phosphoric acid means 
20 pounds, and a quotation of $1 per unit would be 
equivalent to a quotation of 5 cents per pound. In 
the trade, sales are always made on this basis. The 
system is also applied to such nitrogenous products as 
blood, meat, hoof meal, concentrated tankage, etc. 
The price is fixed at so much a unit of ammonia. 



« UNIT" AND « TON" BASES OF PURCHASE 129 

This system is probably the most perfect, and certainly 
cannot but be satisfactory to both the dealer and the 
consumer. It results in the consumer receiving exactly 
as much as he pays for, and the producer is paid for 
exactly what he delivers. The number of units in 
each material sold is fixed in each case by the chemist 
to whom the samples are referred. 

The " Ton " Basis of Purchase 

The other method of purchase is known as the " ton 
basis," and is used almost exclusively in the sale of 
other materials than the standard products mentioned, 
and manufactured fertilizers. This system works well 
with standard high-grade products, since the ton price 
is, in this case, a fair guide as to the cost of the con- 
stituents, though it cannot be as satisfactory as the 
other, since even the best materials may vary suffi- 
ciently to cause a difference in actual cost of the 
constituents, even though the price per ton remains 
unchanged. In this method, the products are usually 
accompanied by a guarantee, the purpose of which is 
to indicate the minimum amount of the constituents 
contained in the material. 

The Necessity of a Guarantee 

In the purchase of mixtures, consumers should 
demand that they be accompanied by a guarantee, 
because they are unable to determine the kind and 
proportion of the different materials entering into 



130 FERTILIZERS 

the mixture, either by its appearance, weight or smell. 
In mixing, too, an opportunity is afforded for dis- 
guising poor forms of the constituents, particularly 
nitrogen. That is, in a mixtiire of nitrogenous 
materials, potash salts and superphosphates, it would 
be a difficult matter to determine, by mere physical 
inspection, the proportion of the nitrogen which had 
been supplied in the form of horn meal and of blood, 
and the statement of the manufacturer on this point 
would be valuable in proportion to his reliability. 
The fact that in mixtures it is impossible for the con- 
sumer to distinguish or determine the proportions, 
amounts or kinds of the constituents is so fully rec- 
ognized that it has resulted in the enactment of laws 
in most states, which require that manufacturers or 
dealers in fertilizers shall state the actual amounts of 
the different constituents contained in their products, 
as well as the sources from which they were derived, 
and which fix a penalty for any failure to complj^ with 
the law in this respect. A chemical control is in these 
cases provided for, and it has been of great service 
both to the good manufacturers, because it tends to 
reduce the number of low-grade brands which would 
naturally come into competition with them without 
such protection, and to the consumers, because it 
protects them from fraudulent products. 

Iauvs Alone do not Fully Protect 

Laws alone, however, are not sufficient to fully 
protect the farmer in this respect. He must possess, 



PURCHASE OF FERTILIZERS 131 

in addition, a knowledge of what constitutes a good 
fertilizer, and must be able to determine from the 
analysis whether there is a proper relation between 
the guarantee and the selling price, and whether the 
materials that have been used are of good quality. 
The fact that there is a very decided lack of the right 
sort of intelligence on this point, is shown by the 
results of the work of the different fertilizer control 
stations. These demonstrate clearly that farmers do, 
in many cases, pay exorbitant prices for their fer- 
tilizer constituents, not because the manufacturer did 
not sell what he claimed to sell, but because the 
price charged by the dealer was far in excess of that 
warranted by the guarantee. For example, it has 
been repeatedly shown that of two farmers in the 
same neighborhood, the one who studies the matter 
and understands the relation of guarantee to selling 
price, may pay 15 cents per pound for his nitrogen, 
while the other, who does not study the matter, buys 
on the ton basis, and does not know that there should 
be such a relation between the two, may pay 30 
cents per pound for the same quality of the same 
constituent. This may be illustrated by the follow- 
ing examples: 

Two brands are offered, made up from the same 
kind and quality of materials. No. 1 is guaranteed 
to contain: 

Nitrogen 1% 

Phosphoric acid (available) 6^ 

Potrieh 1% 



132 FERTILIZERS 

and sells for $20 per ton; and No. 2 is guaranteed to 
contain : 

Nitrogen 4 9& 

Phosphoric acid (available) 8% 

Potash 2% 

and sells for $22 per ton. The farmer who buys on 
the ton basis, or is guided only by the ton price, will 
be induced to purchase the No. 1 brand, because by 
so doing he apparently saves $2 per ton. The one 
who studies the relation of guarantee to selling price 
will purchase the No. 2 brand, because he finds, from 
a simple calculation, that it furnishes the constituents 
at just one -half the cost per pound of the No. 1 
brand, notwithstanding the higher ton price, which 
is shown by the following calculation: 



No. 1 

Lbs. CU. 
per ton per lb. 

Nitrogen 1^^X20= 20 @ 30 = $6 00 

Phosphoric iteid (available) 6% X 20 = 120 @ 10 = 12 00 

Potash 1% X 20 = 20 @ 10 = 2 00 



$20 00 

No. 2 

Lbs. Cts. 
per ton per lb. 

Nitrogen 4^ X 20 = 80 @ 15 = $12 00 

Phosphoric acid ( available )8% X 20 = 160 @ 5 = 8 00 

Potash 2% X 20 = 40 @ 5 = 2 00 

$22 00 
In reality, the fertilizer at $22 per ton is cheaper 
than the one at $20 per ton. 



STATEMENT OF GUARANTEE 133 

Cost per pound of constituents in: 

No. 1 No. 2 

Nitrogen $0 30 $0 15 

Phosphoric acid (available) 10 05 

Potash 10 05 

This may seem an extreme case, but it is well 
within the facts, which may be ascertained by con- 
sulting the bulletins on fertilizer analyses, as pub- 
lished by the different states. 

Method of Statement of Guarantee Sometimes 
Misleading 

Guarantees, too, are sometimes rendered con- 
fusing to the purchaser, because of the method of 
their statement, though the different methods used 
are, in one sense, entirely legitimate, because the 
terms used are in accordance with the facts. From 
a chemical standpoint, at any rate, it is quite as 
legitimate to guarantee the percentage of phosphoric 
acid equivalent to bone phosphate of lime, as it is to 
guarantee the percentage of actual phosphoric acid. 
It is because the consumer believes that the "equiva- 
lent" in combination means that he is obtaining some- 
thing more than when actual constituents only are 
guaranteed, that he is led to purchase more freely, 
or to pay a higher price. Nitrogen may be properly 
stated in its equivalent of ammonia, phosphoric acid 
in its equivalent of bone phosphate, and potash in 
its equivalent of muriate of potash, and it is the 
business of the purchaser to understand the relations 
of the two methods of statement, in order that he 



134 



FERTILIZERS 



may not be misled in his purchases. The following 
table shows the terms used, their equivalents, and 
the factor to use in multiplying, in order to convert 
the one into the other: 



Multiply bv 

Nitrogen 0.8235 

Ammonia 1.214 

Nitrogen 0.1647 

Phosphoric acid . . . 0.458 
Bone phosphate . . .2.183 
Actual potash .... 0.633 
Muriate of potash . . 1.583 
Actual potash . . . .0.54 
Sulfate of potash . . .1.85 



To convert the gv,arante 


' 


f 




Ammonia 




Nitrogen .... 








Nitrate of soda . 








Bone phosphate . 






into an 


Phosphoric acid . 






■ equivalent 


Muriate of potash 






of 


Actual potash . . 








Sulfate of potash 








Actual potash . . 




. 





Discussion of GiKtrantees 



It is shown in this table that, in order to convert 
ammonia into its equivalent of nitrogen, the percent- 
age of ammonia should be multiplied by 82 per cent, 
or divided by the factor 1.214, because ammonia is 
82 per cent nitrogen, and because one part of the 
nitrogen is equivalent to 1.214 parts of ammonia. 

In order to determine the cost per pound of nitro- 
gen in dried blood, which is quoted, for example, at 
$2 per "unit," — 20 pounds of ammonia, — the unit 20 
pounds is multiplied by 82 per cent, which gives 
16.40 as the pounds of nitrogen offered for $2, or 
12.14 cents per pound. 

Bone phosphate of lime is, in round numbers, 46 
per cent actual phosphoric acid. Hence, by multi- 
plying the bone phosphate by 46 per cent, the per 



METHODS OF GUARANTEEIjUO 135 

cent of actucil phosphoric acid is obtained. Ground 
bone, for example, guaranteed to contain from 48 to 
52 per cent bone phosphate, contains, in round num- 
bers, 22 to 24 per cent of phosphoric acid. Sulfate 
of potash is 54 per cent, and muriate of potash is 
63 per cent "actual" or potassium oxide, respectively. 
Hence, to convert the percentages of these forms 
into their equivalents of "actual," they are multiplied 
by the factors given. 

In such raw materials as nitrate of soda, muriate 
of potash, and sulfate of potash, a method of guar- 
anteeing is used which is based upon their purity as 
chemical salts. That is, when pure they contain 100 
per cent of the specific salt, and the guarantee accom- 
panying the commercial product is simply a statement 
indicating their purity. For example, when nitrate of 
soda is guaranteed to contain from 95 to 97 per cent 
pure nitrate, it means that it is 95 to 97 per cent 
pure, or that 3 to 5 per cent of the substance consists 
of impurities ; it is not absolutely pure nitrate of 
soda. Hence, the minimum percentage of nitrogen 
guaranteed is 15.65 per cent, or 95 per cent of 16.47, 
the per cent or pounds per hundred of nitrogen con- 
tained in pure nitrate of soda. When muriate of 
potash is guaranteed 80 per cent muriate, it means 
that 80 per cent of the salt consists of pure muriate 
of potash, and because pure muriate of potash con- 
tains 63 per cent of actual potash, or potassium oxide, 
the actual content of potash is derived by multiply- 
ing the 63 per cent, which the pure salt contains, by 
80 per cent, and the result, 50.5 per cent, represents 



136 FERTILIZERS 

the amount of actual potash guaranteed. Sulfate of 
potash, high-grade, is usuallj^ guaranteed to be 98 
per cent pure, and since pure sulfate of potash con- 
tains 54 per cent of actual potash, the content 
of actual potash, or potassium oxide, guaranteed is 
found \>y multiplying the 54 per cent by 98 per cent. 
The following illustrations show the two methods of 
stating the guarantees of raw materials and of mixed 
fertilizers : 

Raw Materials 

Guarantee on Basis op Purity 

Nitrate of soda 98 %, or containing 98 % pure nitrate 

Muriate of potash . . . . 80 %, " " 80% " muriate 

Sulfate of potash 98%, '• '• 98% " sulfate 

Kainit 25 %, " " 25 % " sulfate 

Guarantee on Basis op Actual Constituents 

Nitrate of soda, total nitrogen 16.00 % 

Muriate of potash, actual potash 50.50 % 

Sulfate of potash, actual potash 53.00 % 

Mixed Fertilizers 
Guarantee on Basis op Equivalents in Combination 

Nitrogen (equivalent to ammonia) 3 to 4 % 

Available phosphoric acid (equivalent to bone phos- 
phate of lime) 18 to 22 % 

Potash (equivalent to sulfate of potash) 10 to 12 % 

Guarantee on Basis op Actual Constituents 

Nitrogen (total) 2.50 to 3.25 % 

Phosphoric acid (available) 8.00 to 10.00 % 

Potash (actual) 5.50 to 6.50 % 



INTERPRETATION OF GUARANTEES 137 

The guarantees of the raw materials mean prac- 
tically the same in the first as in the second case. In 
the first, the percentages given indicate the purity of 
the chemical salt ; while in the second, the figures 
given indicate the actual content of the constituent 
contained in the chemical salt. In large commercial 
transactions, the sales are frequently made on the 
basis of certain purity percentages ; as, for example, 
muriate of potash is sold at so much per ton on the 
basis of 80 per cent muriate. If the analysis shows 
it to contain less than 80 per cent, then the price 
paid per ton is less in proportion to such deficiency. 
If it is shown to contain more than 80 per cent, the 
purchaser pays for the excess at the same rate. In 
round numbers, a ton of muriate on the 80 per cent 
basis contains 1,000 pounds of actual potash; if the 
price is $40 per ton, the cost per pound is 4 cents. 
If analysis shows but 900 pounds instead of 1,000, 
the price paid per ton, at 4 cents per pound, is $36. 
If, on the other hand, it is shown to contain 1,100 
pounds, the price paid per ton is $44. Purchase 
made when this method of guaranteeing is used is 
practically equivalent to the "unit" basis, though, as 
already stated, unless it is thoroughly understood, it 
is likely to be misleading. 

What has been said of the different statements 
of guarantees of the raw materials, is also true in 
the ease of the mixed goods. In the first, the per- 
centages of the elements that are given represent the 
amounts when they exist in combination with other 
elements : nitrogen, as ammonia ; phosphoric acid, 



138 FERTILIZERS 

as bone phosphate, and potash, as sulfate. While 
in the other, the percentages given indicate the con- 
tent of the actual constituents : namely, nitrogen, 
phosphoric acid and potash. 

The Advantages and Disadvantages of Purchasing Raw 
Materials and Mixed Fertilizers 

In the purchase of fertilizers, therefore, two meth- 
ods may be adopted : First, the buying of fertiliz- 
ing materials, as distinct from fertilizers, which fur- 
nish single constituents like the standard high-grade 
products, or which furnish one or two of the con- 
stituents, like ground bone, tankage, fish, and the mis- 
cellaneous products; these are called "incomplete," 
because they do not furnish all of the three essential 
constituents. Second, the purchase of the mixed 
manufactured brands, which contain all of the three 
essential constituents, nitrogen, phosphoric acid, and 
potash, which are prepared to meet the demands of 
different soils and crops, and are called "complete," 
because containing all of the essential raanurial con- 
stituents, or those liable to be lacking in any soil. 
The relative advantage of these different methods 
of purchase depends, first, upon the cost of the con- 
stituents, and second, upon the use that is to be 
made of them. 

It may be urged that, on theoretical grounds, there 
are no good reasons why nitrate of soda, sulfate of 
ammonia, dried blood, superphosphates and potash 
compounds should be mixed, as the manufacture of 



DIFFERENT METHODS OF PORCHASE 139 

these does not improve or change the quality of the 
constituents — it consists chiefly in simply grinding, 
mixing and bagging. There are, however, advan- 
tages and disadvantages in both methods of purchase, 
the chief of which are stated below. 

The advantages in the purchase and use of raw 
materials are : * 

1. A better knowledge of the kind and quality 
of plant -food obtained. That is, these products 
as a rule possess characteristics which distinguish 
them from others and from each other, and they 
are more likely to be uniform in composition than 
mixtures. 

2. It enables the use of one or more of the con- 
stituents as may be found necessary, thus avoiding 
the expense of purchasing and applying those not 
required for the particular crop or soil. The farmer 
is also enabled to adjust the forms and proportions 
of the various ingredients to suit what he has found 
to answer the needs of his soil or crop. 

3. A saving in the cost of plant -food, since in 
their concentrated form, the expenses of handling, 
mixing and rebagging are avoided. 

The chief disadvantages are : 

1. The materials are not generally distributed 
among dealers, and thus not so readily obtained. 

2. It is difficult to spread evenly and thinly pro- 
duets of so concentrated a character, particularly the 
chemical salts, which, unless great care is used, may 



*" First Principles of Agriculture." 



140 FERTILIZERS 

injure by coming in immediate contact with the roots 
of plants. 

3. The mechanical condition or degree of fineness 
is less perfect than in the manufactured products. 

The advantages in the purchase and use of com- 
plete manures are : 

1. They are generally distributed, and can be pur- 
chased in such amounts and at such times as are con- 
venient. 

2. The different materials may be well propor- 
tioned, both as to form of the constituents and their 
relative amount for the various crops. 

3. The products are, as a rule, finely ground and 
well -prepared for immediate use. 

The chief disadvantages are : 

1. That it is impossible to detect in a mixture 
whether the materials are what they are claimed to be. 

2. That without a true knowledge of what consti- 
tutes value, many are led to purchase on the ton basis, 
without regard to the quantity and quality of the 
plant -food offered. 

There is no question that the actual cost of 
the constituent is less when purchased in the fertiliz- 
ing material than in the manufactured brand, as not 
only the expenses of mixing and bagging are saved, 
but the cost of handling the product per unit of 
plant -food is much less in the highly concentrated 
materials than in mixtures made up of both classes 
of fertilizing materials. 

In the purchase of fertilizers by the second method, 
the cost of the constituents is not only higher on the 



HOME MIXING 141 

average, but the variations in their cost are very 
mnch greater, due to the differences in the charges 
made by the different manufacturers for handling and 
selling their products. 

HOME MIXTURES 

The fact that fertilizing materials are a regular 
article of trade, and may be purchased as such, and 
the fact that a complete fertilizer, so-called, is reall}^ 
only a mixture of the various manufactured fertilizing 
materials, has suggested the use of what are called 
"home mixtures," — that is, their mixing by the 
farmer himself. This has proved to be very satisfac- 
tory under proper conditions, since, as already stated, 
the cost of the constituents is much less than if 
secured in the average manufactured brand (often 
from 25 to 50 per cent), and the mixing can be per- 
formed by the regular labor of the farm, and thus 
not add directly to the cost of the constituent. 

This matter of home mixtures has been carefully 
studied by a number of the experiment stations, 
notably Connecticut, Rhode Island and New Jersey. 
The results of their studies are published in their 
regular reports, and show that the materials can be 
evenly mixed on the farm, that the mechanical con- 
dition is good, and that the results obtained from 
their use are entirely satisfactory. It must be remem- 
bered, however, that whatever method of purchase is 
used, the object should be to obtain the kind and 
form of constituent best suited to the conditions 



142 FERTILIZERS 

under which they shall be used, at the lowest price 
per pound. 

In any method of purchase which contemplates 
the use of a mixture, care should be taken in the 
selection of the brand or of the formula, since in 
mixtures as well as in the raw materials, there are 
two grades, the high-grade and the low-grade — 
high-grade in the sense that in quality the con- 
stituents are all good, and in the sense that maxi- 
mum quantities are contained; and second, high- 
grade only in that constituents of good quality 
are furnished. They may be low-grade in the sense 
that both the quality and amount of constituents 
contained are low, and also in the sense that only 
the quality of the constituents is low, the quan- 
tity being sufficiently high. 

Formulas 

The following formulas are used for the sole pur- 
pose of illustrating the differences that may exist 
between high-grade and low-grade mixtures, and not 
as indicating what should be used to make a good 
or poor mixture : 

Formula No. 1 

Nitrate of soda . . 500 lbs. furnishing 80 lbs. nitrogen 
High-grade Buper- 

phosphate . . 1,100 " " 180 " phos. acid avail. 

Muriate of potash, 400 " " 200 " potash 

Total 2,000 " " 460 " total plant-food 



FORMULAS 143 

With a guaranteed composition of : 

Nitrogen 4 % 

Phosphoric acid (available) 9 % 

Potash 10 % 

Formula No. 2 



Nitrate of soda. . . 


250 Jbs. 


furnishing 


40 lbs. nitrogen 


High-grade saper- 








phosphate . . 


1,000 " 


* ' 


160 " phos. acid avail. 


Muriate of potash, 


80 " 


'* 


40 " potash 


Make-weight . . . 


670 " 


<i 




Total 


2,000 " 


240 " total plant -food 



With a guaranteed composition of : 

Nitrogen 2% 

Phosphoric acid (available) 8 % 

Potash 2 % 

Formula No. 3 

_ , „.^ ,, , ... (30 lbs. nitrogen 

Tankage 600 lbs. furnishing- „„ ., 

( 90 phosphoric acid 

Kainit 400 " " 50 " potash (actual) 

Make - weight . . .1,000 " 



Total 2,000 " " 170 " total plant -food 

With a guaranteed composition of : 

Nitrogen 1.5 % 

Phosphoric acid 4.5 % 

Potash (actual) 2.5% 

Formula No. 4 

Tankage 1,200 lbs. furnishingi ^^ ^^f • """'^^^^ . ., 

* ' ^(180 " phosphoric acid 

Kainit 800 " " 100 " potash (actual) 

Total 2,000 " " 340 " total plant-food 



144 FERTILIZERS 

With a guaranteed composition of : 

Nitrogen 2% 

Phosphoric acid 9 % 

Potash f>% 

Formula No. 1 shows a high-grade product, both 
in respect to quality of plant -food and concentration, 
while No. 2 is high-grade only in respect to quality. 
In order that the plant -food may be distributed 
throughout a ton of material, it is necessary to add 
what is called "make -weight," or a diluent. These usu- 
ally consist of substances that possess no direct fer- 
tilizing value. High-grade mixtures cannot be made 
from low-grade materials, and low-grade mixtures 
cannot be made from high-grade materials without 
adding "make -weight." The advantages of high- 
grade products are concentration and high quality 
of plant -food. 

It will be observed that formula No. 1 contains 
nearly twice as much plant -food as No. 2, or, in 
other words, it will require about two tons of a fer- 
tilizer made according to formula No. 2 to secure the 
same total amount of plant -food as is contained in 
one ton of No. 1. Now, the material in No. 2, other 
than the actual plant -food, is of no direct ferti- 
lizing value, — it is of no more value as a fertilizer 
than the soil to which it is applied, — but the 
actual cost of the constituents is considerably in- 
creased, because the expenses of handling, bagging 
and shipping are just double what they would be 
for No. 1. 



DISCUSSION OF FOBMULAS 145 

Formula No. 3 illustrates a low-grade fertilizer in 
the sense that it contains the poorer forms of the con- 
stituents, and furnishes a comparatively small total 
amount of plant -food. The nitrogen is all in the 
organic form, and is derived from tankage, which, 
while not the poorest, is poorer than other forms of 
organic nitrogen. The phosphoric acid is also in 
organic combination, and, while useful under many- 
conditions, is less useful for certain other conditions 
than the soluble in Nos. 1 and 2. The potash > while 
soluble, is derived from kainit, which, because of its 
large content of chlorin, is regarded as less desirable 
for certain crops than the more concentrated materials, 
muriate, or the high-grade sulfate, which is free from 
chlorids. It would require more than 2% tons of a 
mixture made according to this formula to furnish as 
much total plant -food as would be contained in a 
mixture made according to formula No. 1, besides the 
disadvantage of the lower quality of the constituents. 

Formula No. 4 illustrates a mixture which, while 
rich in total constituents, is not high-gi-ade in its 
quality. 

All of these considerations should, therefore, be 
carefully observed in the purchase of mixtures, or even 
in the purchase of raw materials for home mixtures, 
and the analysis, if properly made, will give positive 
evidence on these points. 

The expensiveness of low-grade fertilizers, as repre- 
sented by formulas Nos. 2 and 3, is not fully appre- 
ciated by the purchaser in all cases. He does not stop 
to think that it is quite as expensive to handle the 



146 FERTILIZERS 

material which contains no plant -food as it is to 
handle material which is rich in plant -food. 

The Cost of Handling ^^Male-iveight" 

A comparison of the advantages of low-grade and 
high-grade mixtures in this sense of total quantity of 
plant -food may be illustrated as follows : 

It has been shown by continued studies at the New 
Jersey Experiment Station that the charges of the 
manufacturers and dealers for mixing, bagging, ship- 
ping and other expenses are, on the average, $8.50 per 
ton ; and also that the average manufactured fertilizer 
contains about three hundred pounds of actual fer- 
tilizing constituents per ton. A careful study of the 
fertilizer trade indicates that these conditions are also 
practically true for other states in which large quanti- 
ties of commercial fertilizers are used. 

A mixture of formula No. 1 would contain 460 
pounds of actual available fertilizing constituents per 
ton — 160 pounds, or over 50 per cent more than is 
contained in the average manufactured brand. That 
is, a farmer purchasing a brand similar to formula 
No. 1 would secure in 2 tons as much plant -food 
as would be contained in 3 tons of the average man- 
ufactured brand. Assuming that the charges per 
pound of plant -food at the factory, and the expense 
charges, are the same in each case, and also that the 
quality of plant -food in the one is as good as in the 
other, the consumer would save $8.50 by purchasing 
two tons of the former instead of three tons of the 



CONCENTRATED FEBTILIZEBS 147 

latter. In a few states the consumption of fertilizers 
reaches nearly 100,000 tons annually, while in many 
it ranges from 30,000 to 50,000 tons. 

Thus is shown the very great saving that may be 
effected in the matter of the purchase of fertilizers 
from the standpoint of concentration alone, or, in 
other words, the importance of a definite knowledge 
of what constitutes value in a fertilizer. This saving 
may be accomplished, too, without any detriment to 
the manufacturer, since the difference to him between 
making high-grade or low-grade goods, in reference 
to concentration, is largely a matter of unskilled labor. 
The manufacturers are in the business to cater to the 
demands of the trade. If consumers are intelligent, 
high-grade rather than low-grade goods will [be pro- 
vided by the manufacturers. Furthermore, as already 
indicated, high-grade in the matter of concentration 
means high-grade in quality, for high-grade mixtures 
cannot be made from low-grade products. 

GENERAL ADVICE 

As farmers understand more fully the question of 
fertilization, and as intensive methods of practice are 
adopted, the tendency in the purchase of fertilizers 
will undoubtedly be toward the first method, or the 
purchase of fertilizing materials, rather than mixtures, 
or at any rate, of high-grade special mixtures, rather 
than what are now termed "standard brands," which 
are, as a rule, low-grade in the concentrated sense. 
This tendency will come, first, because intensive prac- 



148 FERTILIZERS 

tice requires a larger use of all of the constituents, 
and second, a greater need in the growth of certain 
crops of specific or dominant elements, and thus better 
results are obtained from the application of single 
constituents, or the use of special formulas, than in 
"extensive" practice, in which the object is more to 
supplement the soil supplies than to fully provide 
for all the needs of the plants for food. 

The tendency toward cooperative buying on the 
part of small farmers will increase as it has done .in 
those countries in which there is a larger use of 
fertilizers than here, though the method is already in 
successful operation in certain sections of the country, 
and with very gratifying results. In this method of 
direct purchase, the manufacturer and the consumer 
are brought into closer relations with each other. 
Transactions are based upon the transfer of a definite 
number of pounds of a specific kind and form of 
plant -food, rather than upon some mysteriously re- 
markable qualities that are claimed, and are by many 
supposed to be inherent in certain mixtures. 



CHAPTER VIII 

CHEMICAL ANALYSES OF FERTILIZERS 

A CGMPLETE chemical analysis of a fertilizer shows 
not only the total amount of the different constituents 
contained in a brand, but the form in which they 
exist, and in most cases, the source of the materials 
used is also indicated. 

THE INTERPRETATION OF AN ANALYSIS 

An analysis may show simply the total amount of 
the constituents. This is not a sufficient guide as to 
the value of a mixture, for while it is not possible to 
indicate absolutely by analysis whether the organic 
nitrogen, for example, is derived from blood (which is 
one of the best forms), or from horn meal (one of the 
poorer forms), it is possible to show whether the nitro- 
gen is derived from nitrate or from ammonia, whether 
the phosphoric acid is derived from a superphosphate 
or a phosphate, and whether the potash present is in 
the form of a sulfate or of a muriate. A high-grade 
or a low-grade fertilizer, for example, may be distinctly 
indicated by the analysis, since it is of a high-grade 
if the three forms of nitrogen are present, if the total 
phosphoric acid is chiefly soluble in water, and if the 
potash has been derived from a sulfate or from a 

(149) 



150 FERTILIZERS 

muriate. On the other hand, if the analysis shows 
that the nitrogen is all in the organic form, that only 
a minimum percentage of the phosphoric acid is 
available, though not soluble, and that a high con- 
tent of chlorin accompanies the potash, it is a low- 
grade product, in so far as the form of the constituents 
is concerned. The following statements of analyses 
of two brands, showing the same total content of 
constituents, illustrate this point: 

Analysis No. T 

Nitrogen, as nitrate 1% 

" " ammonia \% 

" " organic matter 1% 

Total ^% 

Phosphoric acid, soluble 8 %> 

" " reverted \% 

•' insoluble 1% 

Total available 9 % 

Potash 5% 

Chlorin 0.50 % 

A>fALYSIS No. 2 

Nitrogen, as nitrate 

" " ammonia 

" " organic matter 3 % 

Total 3% 

Phosphoric acid, soluble 

•• " reverted 2% 

'• " insoluble S% 

Total available 2 % 

Potash 5 % 

Chlorin 10 % 

A study of these two statements of analyses shows 
that the total contents of the constituents are identical, 



VALUE OF A CHEMICAL ANALYSIS 151 

3, 10 and 5, respectively, in each case. That is, so 
far as the total amounts are concerned, one brand 
furnishes as much as the other, and from that stand- 
point alone it is as good as the other ; but it has been 
already shown that the value of a fertilizer depends 
not only upon the total content of its constituents, 
but upon the form in which they exist. In the first 
brand it is found that two -thirds of the total nitrogen 
exists in the soluble form, equally divided between 
nitrate and ammonia; the remaining third is in the 
organic form, and may be derived from blood, or from 
some low-grade materials. It is to be fairly presumed, 
however, that when thus associated with so high a 
proportion of soluble nitrogen, it is in a good form, as 
the manufacturer has given evidence of his intent by 
his liberal use of other good forms. 

In the case of the phosphoric acid, it is shown 
that of every 100 pounds of the total, 80 pounds are 
soluble, 10 reverted, or nine -tenths of the whole is 
available ; 10 pounds of every hundred only are in- 
soluble, which is not only an indication, but positive 
proof, that the phosphoric acid is derived from a 
superphosphate . 

In the case of potash, the chlorin associated with 
it is but X per cent, indicating that it has been drawn 
from high-grade sulfate, since kainit and muriate 
are rich in chlorin, while in a high-grade sulfate no 
appreciable amounts of chlorin are present. 

In the second statement, all of the nitrogen is 
shown to be in the form of organic matter. It may 
be derived from blood, though it is not likely to have 



152 FERTILIZERS 

been drawn from this source, since of the total 
phosphoric acid but 20 pounds per hundred, or one- 
fifth, is available, and that is reverted rather than 
soluble, indicating that the phosphoric acid must have 
been drawn from tankage or from bone, or other ma- 
terials which contain reverted but no soluble phos- 
phoric acid, and which also contain a considerable 
percentage of nitrogen. The phosphoric acid was cer- 
tainly not drawn from a superphosphate, or it would 
have shown a higher percentage of available, a cer- 
tain proportion of which would have been soluble, and 
the percentage of insoluble would have been very much 
less. In the case of potash, it is quite evident that 
it was drawn from kainit, inasmuch as the percentage 
of chlorin exceeds the percentage of the potash, as 
would be the case if the potash had been drawn from 
that source. 

Thus it is that a complete chemical analysis of a 
fertilizer indicates very clearly the source of the 
materials by the form in which the constituents exist 
in the mixture. 

THE AGRICULTURAL VALUE OP A FERTILIZER 

It is obvious, from what has already been pointed 
out, that the value of a fertilizer to the farmer 
depends not so much upon what is paid for it as upon 
the character of the materials used to make it. This 
value is termed the "agricultural value," and it is 
measured by the value of the increased crop produced 
by its use. It is, therefore, a variable factor, depend- 



AQBIOULTUBAL VALUE OF A FERTILIZER 153 

ing first, upon the availability of its constituents, and 
second, upon the value of the increased crop produced. 
For example, in the first place, the agricultural 
value of a pound of soluble phosphoric acid is likely 
to be greater than that of a pound of insoluble when 
applied under the same conditions as to soil and crop, 
because in the one case the element is in its most 
available form, while in the other it is least available. 
In the second place, the soluble phosphoric acid may 
exert its full effect and cause a greatly increased yield 
on a certain crop, and still not cause an increase in its 
value sufficient to pay the cost of the application, 
while for another crop the same application may 
result in a very great increase in the value of the 
crop. The character or form of the materials used in 
a ^mixture, as well as their suitability for the crop 
must, therefore, be carefully considered in the pur- 
chase of fertilizers. Slow- acting materials cannot be 
expected to give profitable returns, particularly upon 
quick -growing crops, nor expensive materials such 
profitable returns, when used for crops of relatively 
low value, as for crops of relatively high value. 

THE COMMERCIAL VALUE OF A FERTILIZER 

This agricultural value is, however, separate and 
distinct from what is termed "commercial value," or 
cost in market. This value is determined by market 
and trade conditions, as the cost of production of 
the crude materials and the cost of their manufacture 
and sale. Since there is no strict relation between 



154 FERTILIZERS 

agricultural and commercial or market value of a fer- 
terlizer constituent, it frequently happens that an 
element in its most available form, and under ordi- 
nary conditions of high agricultural value, costs less 
in market than the same element in less available 
forms and of a lower agricultural value. The cost of 
production in the one case is lower than in the other, 
though the returns in the field are far superior. 

It is manifestly impossible to fix an agricultural 
value for any of the constituents that will be true 
under the varying conditions of soil, crop and season, 
and method of use, though the relative value of the 
different forms under uniform conditions of use may 
be fairly indicated, and the analysis is the guide as 
to their form. The commercial value of the different 
constituents in their various forms may, too, be fairly 
indicated, and will vary according to variations in 
trade conditions. If the wholesale jobbing price of 
nitrogen as nitrate is 15 cents per pound, available 
phosphoric acid 5 cents per pound, and potash 4 cents 
per pound, these are the prices which the manufacturers 
pay. Their increased cost in manufactured brands, 
therefore, is in proportion to the cost of this work ; 
hence their cost to the consumer at factory should 
vary within reasonably narrow limits, due to varia- 
tions in cost of manufacturing in different localities. 

An illustration of the commercial value i.s shown 
by the following example : Suppose that nitrate of 
soda costs or can be purchased at retail, in ton lots, 
for $48 per ton, which is, then, its commercial value. 
The commercial or trade value of the nitrogen is, 



COMMERCIAL VALUE OF A FERTILIZER 155 

therefore, 15 cents per pound, since a ton contains on 
the average 320 pounds of nitrogen. Or, suppose 
that the retail price of available phosphoric acid in 
superphosphates is $1 per unit ; this is its commercial 
value, and hence the commercial or trade value of 
the available phosphoric acid would be 5 cents per 
pound, since a unit contains 20 pounds. It does 
not follow that the application of a pound of nitrogen, 
costing 15 cents, and, therefore, having a commercial 
value of 15 cents, will result in an increased crop 
worth 15 cents, or that the application of a pound of 
phosphoric acid costing 5 cents per pound will result 
in an increased crop worth 5 cents. The increased 
returns in crop from their use may be very much 
greater or much less than the cost of the constituents, 
depending upon the kind of crop and the skill of the 
user. In the purchase of materials, however, a com- 
mercial valuation is a guide as to the cost of the con- 
stituents from different manufacturers or dealers ; and 
in many states a system of commercial values for 
mixed fertilizers has been fixed, which, when properly 
understood, is a useful method of comparison of the 
different brands. 

This method is based upon the fact that at points 
of supply a pound of nitrogen, in the form of nitrate, 
of ammonia, or of definite organic compounds, or a 
pound of available phosphoric acid, or of potash in 
the form of muriate or sulfate, is practically the same 
to all manufacturers. That is, these cost prices, or 
trade values, when applied to the constituents in the 
mixture, represent their commercial value before tliey^_ 



156 FERTILIZERS 

are mixed to form complete fertilizers. Hence, the 
difference between the valuation of a brand on this 
basis and the cost to the consumer represents the 
charges, including profit, for mixing, bagging, ship- 
ping and selling the goods. 

The commercial or trade value for each of these 
constituents is obtained, as already indicated, by 
simply calculating the cost, using two factors, — 
the wholesale prices for the different materials con- 
taining them, and their average composition. To 
this cost is added a certain percentage, to represent 
the cost of handling and distribution in small lots. 
Thus the trade value corresponds as nearly as may 
be with the cost of the constituents to the farmer. 
That is, the price fixed represents what the farmer 
would have to pay the manufacturer for the con- 
stituents in the material before it is mixed. 

For example, suppose the wholesale price per ton 
of nitrate of soda for the six months preceding March 
1 is shown to be $40 ; the wholesale cost of nitrogen 
in this form is, therefore, 12.5 cents per pound. To 
this wholesale price may be added a certain sum to 
cover the expenses of handling, usually 20 per cent, 
thus making the retail price per ton $48, and the 
trade or commercial value of the nitrogen 15 cents 
per pound. That is, the $48 per ton, or 15 cents 
per pound, represents the retail cost per pound of 
nitrate nitrogen. This, if applied to the nitrogen as 
nitrate, in the mixed fertilizer, will show what it 
could have been bought for as nitrate in the unmixed 
fertilizer. The values for the other constituents are 



SCHEDULE OF TRADE VALUES 157 

derived in the same way. These, together, make the 
schedule of trade or commercial values of the con- 
stituents which are used in the computing of the 
commercial values of mixed fertilizers. The schedule 
of values is revised annually, and, as nearly as pos- 
sible, at the same time in the year. The following 
schedule, used as an illustration of this point, was 
adopted for 1898 by the states of New York, Con- 
necticut, Rhode Island, Massachusetts, Vermont and 
New Jersey: 

Schedule of Trade Values Adopted by Experiment 
Stations for 1898 

Cts. per lb. 

Nitrogen, as nitrates 13.0 

" " ammonia salts 14.0 

Organic nitrogen, in dried and fine-ground fish, meat and 

blood, and in mixed fertilizers 14.0 

Organic nitrogen, in fine-ground bone and tankage* .... 13.5 
" " " coarse bone and tankage t 10.0 

Phosphoric acid, soluble in water 4.5 

" " " " ammonium citrate i 4.0 

" " insoluble, in fine bone and tankage* . . . 4.0 

" " " " coarse bone and tankaget . . 3.5 

" " " " mixed fertilizers 2.0 

" " " " fine -ground fish, cotton -seed 
meal, castor pomace and wood ashes 4.0 

Potash, as muriate 4.25 

" " sulfate, and in forms free from muriates (or 
chlorids) 5-0 



♦Finer than 1-50 inch. 

t Coarser than 1-50 inch. 

tin New Jersey, the price for the soluble and reverted is identical; Tii., 
4.S cents, owing to the diiferent method used in the determination of th« 
"rererted." 



158 FERTILIZERS 

It will be observed that the schedule gives the 
cost per pound of the different forms of nitrogen, 
and of high - grade organic nitrogenous materials ; of 
nitrogen and phosphoric acid in ground bone and 
tankage ; of available phosphoric acid in superphos- 
phates, and of actual potash in the potash salts, and 
is a useful guide also in showing that the nitro- 
gen, phosphoric acid and potash contained iu these 
materials can be purchased in ton lots for the 
prices mentioned. The valuations of mixed fertilizers, 
obtained by the use of this schedule, are entirely 
commercial; they are not intended to indicate even a, 
possible agricultural value. This point needs to be 
emphasized, as many are inclined to interpret them 
as not only guides as to agricultural value, but as 
positive statements of such value. It can be said, 
however, that those who do so do not familiarize 
themselves with the discussions that usually accom- 
pany reports of analyses. The different trade values 
given for the nitrogen and phosphoric acid in the 
two grades of bone represent their value in the form 
of ground bone and of bone meal, products which 
are distinctly recognized in the market, and which are 
quoted at different prices. The coarser ground bono 
is lower in price than the finer bone meal. 

The accuracy of the schedule of values can be 
shown by comparing it with the actual prices paid 
for the constituents in the different materials, and 
such comparisons as have been made from year to 
year, by a number of the institutions exercising an 
analysis control, show that manufacturers and dealers 



OBJECTIONS TO COMMERCIAL VALUES 159 

are willing to sell to farmers at prices corresponding 
very closely with the schedule.* 

A value is placed upon the insoluble phosphoric 
acid in mixed fertilizers, not because all insoluble costs 
the price given, but because in mixtures it is assumed 
that the phosphoric acid is drawn from organic sources, 
which do cost, at least, the price given. 

There are arguments both in favor of and in oppo- 
sition to this method of comparing the commercial 
values of mixed fertilizers. The chief arguments in 
opposition may be stated as follows: 

First, that the prices of these materials vary, and 
hence in order to represent the actual commercial value 
at the time the sales are made, they should be changed 
as the markets change. 

Second, the valuations are misleading, because the 
farmer does not clearly understand their meaning, and 
is thus guided in his judgment of the usefulness or 
agricultural value of a fertilizer by the stated com- 
mercial value, as shown by this method, rather than by 
the kind, form and proportion of constituents that 
may be contained in it, and upon which its agricultural 
value should be based. 

Third, the chemical analysis does not show abso- 
lutely the sources of the materials, and thus it is 
diflBcult to place a true commercial value upon a mix- 
ture. This is especially true of organic nitrogen, 
since because it is impossible to separate the amounts 
that may be derived from different materials, a uniform 

*Se« Bolletins Connecticut and New Jersey Experiment Stations. 



160 FEBTILIZERS 

value is placed upon the total nitrogen found, whether 
it is derived from the best forms, as dried blood and 
dried meat, or whether derived from horn meal, ground 
leather, or other low-grade forms of nitrogenous 
material. This encourages the use of low-grade 
products by unscrupulous manufacturers, to the real 
detriment of the trade as a whole. 

Fourth, that the commercial value so fixed mili- 
tates against the use of certain kinds of good materials, 
and in favor of certain kinds of poorer materials. 
That is, a valuation of 2 cents per pound for insoluble 
phosphoric acid in complete fertilizers, for example, is 
a direct encouragement to include in the mixture a 
considerable proportion of the insoluble phosphoric 
acid from South Carolina, and other rock phosphates, 
the value of which is ignored in commercial transac- 
tions ; while that price (2 cents) does not give a fair 
value to the phosphoric acid contained in bone, tankage 
and natural guanos, products in which the commercial 
value of the insoluble is recognized, — that is, mixtures 
which contain bone and tankage, and which furnish 
phosphoric acid largely in an insoluble form. The 
valuation fixed for this form is too low to fully 
represent the commercial value of these goods. It is 
also said that the trade value for available phos- 
phoric acid in the mixtures encourages the use of 
superphosphates from the rock phosphates, and dis- 
courages the use of superphosphates from bone-black, 
bone -ash and dissolved bone, because the trade or 
commercial values represent the average cost of availa- 
ble phosphoric acid in the superphosphates from all 



THE ADVANTAGES OF VALUATIONS 161 

of these, while the latter materials, because of actual 
commercial conditions, cost more than the superphos- 
phates from the former. 

The chief arguments in favor are: 

First, that it is not asserted that the system shows 
absolutely the commercial value of each brand at the 
time the sales are made, but the comparative com- 
mercial value. 

Second, They are not misleading. The commercial 
valuations are not intended to be a guide as to the 
agricultural value of a fertilizer. It is distinctly stated 
in the reports of analyses that the comparative values 
are purely commercial. 

Third. It is a S5^stem which more nearly approaches 
perfection than any other that has been devised, is 
educative in its tendency, and is a safe guide, in the 
majority of instances, as to the charges made for 
mixing, handling and selling plant -food contained in 
the different brands. If the analysis is properly in- 
terpreted, as already indicated, it is the purchaser's 
fault if he buys poor forms of plant -food at a high 
price. It is certainly a safer guide than mere name 
of brand, and does not encourage the use of poor 
materials. 

Fourth. Any system of comparison of brands must 
leave a great deal to the judgment of the purchaser. 
He must interpret for himself whether he would rather 
that his phosphoric acid were derived from one source 
or another, whether he would prefer to pay a higher 
price for insoluble phosphoric acid in acid phosphate, 
and have the remainder soluble, than to pay the same 



162 FERTILIZERS 

or a greater price for the insoluble phosphoric acid in 
bone, and have the remainder of it in the reverted 
form. These conditions are again indicated by the 
analysis which accompanies the valuation ; the valua- 
tions are, therefore, not to be used in total disregard 
of the composition. If they are so used, it is not the 
fault of the system. That it militates against the use 
of high-priced superphosphates, if thej^ are no better 
than the lower- priced ones, is no argument against 
the system, but rather for it, since it tends toward a 
readjustment of the prices, a condition that must be 
met in all competitive trades. Furthermore, the valua- 
tion system has been effective in driving out materiahs 
that are either fraudulent in their character or of very 
low-gi*ade. It is impossible to obtain a high valuation 
on poor materials, and in the majority of cases de- 
pendence upon valuations alone would be a safe guide 
as to the comparative agricultural value of brands of 
the same general composition. 

CALCULATION OF COMMERCLA.L VALUES 

The following examples illustrate how commercial 
values of complete fertilizers and of ground bone are 
calculated. The mixed, or complete fertilizer, contains 
the three fonns of nitrogen, three of phosphoric acid, 
and the two forms of potash. In the bone, it is 
assumed that 50 per cent of the meal is finer than 
1-50 inch, and is, therefore, regarded as fine, and that 
50 per cent is coarser than 1-50 inch, and is, therefore, 
regarded as coarse ; and it is also assumed that the 



CALCLTLATION OF COMMERCIAL VALUES 



163 



proportions of the nitrogen and phosphoric acid in 
the fine and coarse is the same ; also, that the analysis 
shows the bone to contain 4 per cent of nitrogen and 
20 per cent of phosphoric acid. 

A Complete Fertilizer 



Nitrogen, as nitrates . . . 

" " ammonia salts 

" " organic matter 

Phosphoric acid, soluble . 

" " reverted 

" " insoluble 

Potash, as muriate . . . 

" " sulphate ... 



< or lbs. 
per 100 

. . 1 X 20 : 

. 1 X 20 : 

. 1 X 20 : 

. 8 X 20 : 

. 1 X 20 : 

. 1 X 20 : 

. 5 X 20 = 
. 5 X 20 = 



Lbs. 
per ton etn 

= 20 X 13.0 

= 20 X 14.0 

= 20 X 14.0 

=160 X 4.5 

= 20 X 

= 20 X 

=100 X 

=100 X 



Yabie Estimated valve 
per lb. per tan of each 
constituent 

■■ $2 



4.5 
2.0 
4.25 
5.0 



60 

2 80 

2 80 

7 20 

90 

40 

4 25 

5 00 



Total estimated value per ton $25 95 

The first column shows the per cent of the con- 
stituents contained, which, multiplied by 20, gives the 
pounds per ton in the second column, which, multiplied 
by the schedule prices per pound, gives the valuation 
per ton, as shown in the fourth column. 



1 2 

/• or lbs. 5t of 
per fine- 
100 ness 



Ground 

3 



Bone 



i or lbs. Lbs. 

per 100 per ton 

j 4 X 50= 2 in fine. X20= 40 X 

( 4 X 50= 2 in coarse. X 20= 40 X 

PhosphoricJ20 X 50 = 10infine. X20 = 200 X 

acid . (20 X 50 =10 in coarse. X 20 =200 X 



Nitrogen 



Value 

per lb. 

ets. 

13.5 


Estimated 

value 

per ton 

= $5 40 


10.0 


= 4 00 


4.0 


= 8 00 


3.5 


= 7 00 



Total estimated value per ton $24 40 



1G4 FERTILIZERS 

The first column of figures shows the per cent, 
or pounds per hundred, of the constituents, which is 
multiplied by the percentage of fineness, which gives 
the percentage or pounds per hundred of fine or 
coarse in the third column. The calculation is then 
finished as in the case of complete fertilizers. 

THE UNIFORMITY OF MANUFACTURED BRANDS 

Another point which consumers of fertilizers are 
interested in is the reliability of the various brands. 
That is, they desire to know whether a brand that 
shows good forms of nitrogen, of phosphoric acid, and 
of potash in one year may be depended upon to fur- 
nish approximately the same the following year, or 
whether the manufacturers change their formulas from 
year to year to conform to the relative cost of the 
different materials : that is, whether when nitrogen 
is relatively expensive and phosphoric acid is rela- 
tively cheap, they introduce a larger proportion of 
phosphoric acid and a smaller percentage of nitrogen; 
whether when organic nitrogen is cheap and nitrate 
and ammonia nitrogen are dear, they change the pro- 
portions of these to correspond with the difference 
in price, in order to retain the same selling price. 

This is an important point, since after a certain 
brand has been shown to be better suited than 
another to their conditions of soil, to change the 
formula, both in reference to the character and pro- 
portions, may mean to the purchaser the difference 
between profit and loss. 



UNIFORMITY OF MANUFACTURED BRANDS 165 

Evidence on this point can be obtained from the 
reports showing the results of the analyses of the dif- 
ferent brands from year to year, and a careful 
study of these shows that genuine manufacturers of 
fertilizers, — those who make it their sole business, 
rather than a side issue or an adjunct to another busi- 
ness, — can be fully depended upon in this respect. 
They know that the farmer's interest is their interest, 
and that their sales will depend, other things being 
equal, upon the increased crop results that the farmer 
secures ; that the permanency and success of their 
business will depend upon the successful and profitable 
use of their product ; and that they cannot afford to 
and do not change their formulas from year to year, 
either in proportion or quality of constituents, to cor- 
respond with the changes in price of the materials. 
Their brands can be depended upon to furnish prac- 
tically the same amount, kind and proportion of 
plant -food from year to year. 

The value of a fertilizer depends upon the kind, 
quality and form of plant -food, as shown by the 
analysis. Value does not depend upon who the manu- 
facturer is, or what the statements may be concerning 
the usefulness of special manipulation, nor to any 
great extent upon special formulas, unless the farmer 
has positive knowledge of the character of his own 
conditions. Formulas derived both in kind and pro- 
portion from the same materials will do equally well 
under the same conditions. So far as the matter has 
been investigated, there is no specific virtue added by 
what is claimed to be the "blending" of the materials. 



166 FERTILIZERS 

In the whole matter of the purchase of fertilizers, 
no guide, however good, can take the place of intel- 
ligence on the part of the purchaser. This intelli- 
gence must be exercised in the selection of forms of 
plant-food, in the preparation of formulas, in the 
interpretation of guarantees and of commercial values, 
and in the method of using the fertilizer. 



CHAPTER IX 

METHODS OF USE OF FEBTILIZEBS 

The primary object in the use of a commercial fer- 
tilizer is to receive a profit from the increase in the 
yield of crops from the land to which it is applied; 
and this may be derived either from the immediate 
crop, or from the larger yield of a number of crops. 
That the greatest immediate or prospective profit may 
be gained, a wide knowledge of conditions which have 
either a direct or indirect bearing upon the result is 
essential. 

CONDITIONS WHICH MODIFY THE USEFULNESS OF 
FERTILIZERS 

In fact, the controlling conditions surrounding the 
matter are so numerous and so various that it is im- 
possible, with our present knowledge, to lay down 
positive rules for our guidance. At best, only sug- 
gestions can be offered. 

We may possess a full knowledge of both the kind 
and form of existing fertilizer supplies, their cost and 
the action under known conditions of the constituents 
contained in each, as well as their maximum capability 
for increasing the crop, but together with this knowl- 
edge, it is essential that we should know how these 

U67) 



168 FERTILIZERS 

facts and principles must be applied to each individual 
crop, soil and condition, and yet even with this, abso- 
lute certainty of profit is not guaranteed. A few of 
the more important conditions which control the 
profitable use of fertilizers are, therefore, briefly dis- 
cussed, in order to arrive at a better understanding of 
the practical suggestions and concrete examples given 
in subsequent chapters. 

Derivation of Soil a Guide as to its Possible 
Deficiencies 

The first consideration is the soil itself, and its 
influence. It is well known that a wide difference 
exists in soils, both in reference to their chemical 
character or composition, and to their physical proper- 
ties, each having a direct influence in determining the 
effect of any specific application of fertilizers. These 
differences in soils are due to changes which were 
wrought in the surface of the earth during its forma- 
tion, and which are continuing in a small way at the 
present time. It is believed that the original earth 
crust contained all the minerals now found in it, but 
that in the beginning they were distributed more uni- 
fromly throughout its mass, and that the soils as they 
exist at the present time, and as a result of the direct 
disintegration of the original rock, represent a very 
small area of the earth's surface. They are not now 
constant, but variable in their character. The various 
changes that have taken place during geologic time 
have resulted in the breaking up of the original rocks, 



SOILS DIFFER IN CHEMICAL COMPOSITION 169 

a part having been separated mechanically and being 
represented by various sizes of particles, and a part 
rendered soluble. The fragments and the soluble por- 
tions thus separated have not been deposited again in 
the same proportions as they existed in the original 
rock, which has caused a very wide variation in the 
chemical composition of the different soil deposits. 
The process and its results may be shown at the present 
time in the wearing away of rocks. The harder, 
sandy particles separate mechanically, and because of 
the difference in the size of the particles, the coarser 
are deposited as gravel or sand, in one place, and the 
finer particles are deposited in another, making the 
clay. The lime enters partly into solution and is de- 
posited in another place, and so on, thus giving us 
sandy soils, clayey soils and limy soils, all differing 
from each other in their amount and proportion of the 
essential fertilizing constituents, as well as in their 
physical qualities, — the sandy and gravelly making the 
poorest soils because the particles consist very largely 
of quartz, and the remainder being poor in phosphoric 
acid or potash. The clay soils are frequently rich in 
minerals containing potash, and poor in those con- 
taining lime and phosphoric acid; and the limestone 
soils are poor in potash and rich in lime, and fre- 
quently in phosphates. In addition to these soils, 
there are those that are made up largely of vegetable 
matter, due to the accumulation of decaying growths. 
These are frequently rich in nitrogen and poor in all 
of the essential mineral constituents. 

Hence it is that in the use of a commercial fertilizer, 



170 ySBTILIZERS 

at least for certain crops, a knowledge of the nature 
of soils in respect to the possible deficient element is 
important, in order that those which exist in abun- 
dance may not be added to, but that they may be sup- 
plemented by such an abundance of the deficient ele- 
ments as to permit the acquirement by the crops of 
those necessary for a maximum growth. As a rule, 
potash is a very essential constituent of manures for 
sandy soils, not only because all crops require potash, 
but because they require it in relativelj^ large amounts, 
and because in sandy soils it is liable to exist in 
minimum amounts. Potash fertilization, therefore, is 
especially useful on sandy soils. On the other hand, 
in clay soils, which, as a rule, contain a very con- 
siderable proportion of potash as compared with sandy 
soils, the deficient element may be either phosphoric 
acid or lime; and if these are supplied in abundance, 
the plant will be able to secure the necessary potash. 
In a limy soil, the lime and phosphoric acid, and per- 
haps the potash, may be in sufficient abundance to 
cause a normal growth of plant, yet the nitrogen may 
be so deficient as to prevent a normal growth. 

Physical Imperfections of Sandy Soils 

If it were possible to distinctly classify soils in 
respect to their lack of one or more of the essential 
constituents, it would be an easy matter to formulate 
rules for our guidance in the fertilization of these 
soils; but such is not the ease. Even sandy soils vary 
widely in their chemical composition, as well as in 



SOILS DIFFER IN PHYSICAL CBARACTEB 171 

their mechanical or physical properties, and certain 
of them possess such a physical character as to make 
it impossible to grow maximum crops even though 
the essential elements are all supplied in sufficient 
abundance. The constituent particles are too coarse, 
and thus make the soils so open and porous that 
they too freely admit the air, water and warmth, and 
thus results a very rapid drying and heating of the 
soil, with a premature ripening and burning of the 
crops. The phosphates or the potash compounds ap- 
plied are not readily fixed, and suffer an immediate 
loss as soon as rain falls in such amounts as to 
cause a leaching from them. 

Physical Imperfections of Clay Soils 

In clay soils, the physical conditions are quite the 
reverse. All clay soils do not have the same general 
composition, and they differ widely in their physical 
qualities. Certain of them possess a reasonably good 
texture, and permit the absorption of the food applied, 
as well as its gradual distribution throughout the 
mass by the percolation of the water through them; 
while certain others are so compact, owing to the 
finely divided particles, that even though they were 
abundantly supplied with all or the necessary mineral 
constituents, profitable crops could not be grown 
because the roots could not readily penetrate, and 
because the water falling upon the land would not 
readily pass through, but remain upon the surface. 

In the case of soils with an abundance of lime, 



172 FERTILIZERS 

physical qualities also exercise a very considerable 
influence, even though there is a sufficient supply of all 
of the fertility elements. Certain of them are too cold, 
others are too dry, and the mechanical condition is 
such as to prevent the proper and uniform growth of 
plants. It must be remembered, then, that only gen- 
eral rules apply in the use of fertilizers upon soils of 
the different classes, and that they are modified by 
both the chemical composition and the mechanical con- 
dition of the soils. The best use of a fertilizer, — that 
is, the greatest proportionate return of plant -food in the 
crop, all things considered, — is obtained from its ap- 
plication upon soils that possess "condition," or that 
are well cultivated or managed. Full returns cannot 
be expected when they are applied upon soils that are 
too wet or too dry, too porous or too compact, or too 
coarse or too fine. It is important that even the best 
soils should be properly prepared, and it is infinitely 
more important that those which possess poor mechan- 
ical condition should be improved in this respect, 
before large expenditures are made for fertilizers. 

The Influence of Previous Treatment and Cropping 

In the next place, the previous treatment and 
cropping of soils should guide in the use of fer- 
tilizers, since soils of the same natural character, 
located equally well, will not always show the same 
results from the application of fertilizers, because in 
the one case the cropping has been such as to result 
in the rapid exhaustion of one, rather than the three 



INFLUENCE OF PREVIOUS CROPPING 173 

specific fertilizer elements ; while in the other, the 
cropping may have been quite as severe, but has been 
helpful because judicious rotations have been used and 
improved methods practiced. It may be that in the 
one case, there may have been a continuous cropping 
of wheat, for example, and only the grain sold from 
the farm, in which case there would be a much more 
rapid exhaustion of the nitrogen and phosphoric 
acid than of the potash ; and if this continuous 
wheat -cropping has been continued for a long time, 
an application of the phosphates only may result in 
quite as large an increase in crop as if both phos- 
phates and potash salts were applied, because the 
potash exhaustion has been less rapid than that 
of the phosphoric acid, and the addition of potash 
would simply add to the probably abundant quantities 
already there. On the other hand, if the cropping 
has been timothy hay, the removal of the potash 
would have been greatly in excess of the phosphoric 
acid, and consequently a fertilization with a greater 
proportion of potash, or even this element alone, of 
the minerals, may result in quite as large returns 
as if the fertilization had consisted of both phosphoric 
acid and potash. In fact, if the land had been 
cropped continuously with tobacco, cotton, potatoes, 
or other crop, there is likely to be a much larger 
removal proportionately of some one element, rather 
than proportionate amounts of all. This practice 
results in a disproportionate removal of the constitu- 
ents, and in order to bring the land back to its 
capacity for maximum production, or to equalize 



174 FERTILIZERS 

matters in this respect, it is necessary to add to the 
soil the constituents removed in amounts in excess 
of the others. On the other hand, the cropping may 
have been such as to be fully as exhaustive in the 
iSense that the total quantity of constituents removed 
is quite as great, though since they are removed in 
more uniform proportions, the period of profitable 
cropping is extended, and the fertility needed includes 
all the essential elements, rather than one or two. 
That is, the grain, hay and potatoes may have been 
grown in rotation, each removing one or the other in 
greater proportion, but because thej^ differ with each 
crop, no one is exhausted before the other; and thus 
when the land reaches the time when it would no 
longer profitably grow those crops, an application 
then of all of the constituent elements would result in 
a greater and more profitable increase in crop than 
if the fertilizer contained one constituent only. The 
previous treatment and cropping of soils, therefore, 
is an important guide in determining the most 
economical method of fertilization. 

Furthermore, in this matter of cropping as a guide 
to possible need of fertilization, it must be remem- 
bered that a continuous one -crop practice is more 
productive of total loss of constitueuts than a prac- 
tice which includes such renovating crops as clover, 
or one which permits of a more constant occupation 
of the land, since in the former, the introduction of 
clover reduces the need for nitrogen fertilization, and 
in the latter, the vegetable matter is not so rapidly 
used up, and the loss of mineral constituents by 



INFLUENCE OF CHARACTER OF CROP 175 

mechanical and other means is very much reduced, 
because of the constant occupation of the land. 

The Influence of Character of Crop 

The financial result from the application of fer- 
tilizers is also influenced in a very large degree by 
the character of the crop itself, whether the value 
of an increase in crop as great as can be expected 
from a definite application is high or low ; and on 
this basis, crops may be classified into two general 
groups : first, those which possess a high fertility, and 
which, as a rule, possess a relatively low commercial 
value; and second, those which possess a low fertility 
v<alue and a relatively high commercial value. In the 
first class are included the cereal and forage crops, 
as corn, oats, wheat, hay, buckwheat, cotton and 
tobacco, and in the second are included the various 
vegetable and fruit crops. This classification, and 
its importance, may be illustrated by the following 
examples : 

A ton of wheat, at $1 per bushel, will bring 
$33.33. Its sale removes from the farm 38 pounds 
of nitrogen, 19 of phosphoric acid, and 13 of potash. 
At prevailing prices for these constituents, it would 
cost $6.50 to return them to the farm. 

A ton of asparagus shoots, at 10 cents per pound 
bunch, will bring $200. Its sale removes from the 
farm 6 pounds of nitrogen, 2 of phosphoric acid and 
6 of potash, which could be returned for but little 
more than $1. 



176 FERTILIZERS 

A ton of timothy hay will bring $10. Its sale 
removes from the farm 18 pounds of nitrogen, 7 of 
phosphoric acid and 28 of potash, amounts that 
would cost $4. 

A ton of apples will bring in an ordinary season 
$20. It removes less than 3 pounds of nitrogen, 1 of 
phosphoric acid and 4 of potash, which would cost 
less than 60 cents to return to the land. 

It is thus shown that crops like wheat and hay 
possess a relatively low commercial value, and yet 
carry away, when sold, a very considerable amount 
of the fertilizing constituents, while vegetables and 
fruits, as illustrated by the asparagus and the apples, 
have a high commercial or market value, and carry 
away but minimum amounts of the fertilizing con- 
stituents. This distinctive character of crops, while 
not an absolute guide as to the profits that may be 
obtained from the use of fertilizers, — since the cost of 
production varies widely for each class, — is instruc- 
tive in showing that those of a low commercial value 
are more exhaustive than the other class, or those of 
a high market value, and is certainly suggestive, 
pointing out the necessity for judgment in the ap- 
plication of fertilizers that shall be made in the 
case of crops of the different groups. 

The Kind of Farming, Whether ^^ Extensive or Intensive" 

Another very important consideration, and one which 
exercises an influence, is whether the farming engaged 
in is "extensive" in its character, or "intensive;" 



CBARACTERISTICS OF GROWTH 177 

whether the purpose or idea is to simply supplement the 
stores of plant -food in the soil, or whether the object 
is to ensure an abundance of all forms of constituents 
under all reasonable conditions, in order that a 
maximum production may be secured. 

PLANTS VARY IN THEIR POWER OF ACQUIRING POOD 

In the next place, the character or feeding capacitj' 
of the plant and its season of growth should be con- 
sidered, that systematic methods may be adopted, and 
thus not only that waste of fertilizing materials may 
be avoided, but that the applications may be made at 
such times and in such amounts as will, other things 
being equal, promote the greatest increase per unit 
of applied food. 

While each plant possesses individual characteristics 
which distinguish it from all others, for our purpose 
they may again be classified into general groups which 
possess somewhat similar characteristics, particularly as 
to their method and time of growth and their capacity 
for acquiring food from soil sources. 

Characteristics of the Cereal Group 

The cereals possess distinct characteristics of 
growth. The roots branch just below the surface, and 
each shoot produces feeding roots, which distribute 
themselves in every direction, and thus absorb food 
from the lower layers of the soil as the plant grows 
older. Because of their wide root sj'stem, and because 



178 J^A HTILIZERS 

of the character of ther feeding rootlets, they are 
able readily to acquire food from the insoluble phos- 
phates and potash compounds of the soil, though they 
are unable to feed to any extent upon the insoluble 
nitrogen. Furthermore, inasmuch as the most rapid 
development of many of these crops takes place early 
in the summer, before the conditions are favorable for 
the rapid changing of organic nitrogen into nitrates, 
they are, with the exception of Indian corn (maize), 
specifically benefited by early applications of nitrogen 
in the form of nitrate. The corn, on the other hand, 
which makes its most rapid growth after the other 
cereals are harvested, — in July or August, — when 
the conditions are particularly favorable for the de- 
velopment of nitrates, do not usually require as large 
proportions of nitrogen as of the mineral constituents, 
particularly the phosphates. That is, wheat, rye, oats 
and barley are specifically benefited by the early appli- 
cation of quickly available nitrogen. 

Characteristics of Grasses and Clovers 

Forage crops, including both the grasses and clovers, 
constitute another group, in so far as their use is con- 
cerned, though possessing marked distinguishing char- 
acteristics. Of the grasses, nearly all species are 
perennial, though their length of life depends upon 
the method of cropping and upon the character of 
the soil. They send their fibrous roots into the sur- 
face soil in the same manner as the cereals, though 
they differ from them in forming a set of buds whioh 



CHABACTEBISTICS OF OBOWTH 179 

become active in the late summer and develop new 
roots and shoots. , They resemble the cereals in their 
power of acquiring mineral food, and are even more 
benefited by the application of nitrogen, since the 
chief object in their use is to obtain the nitrogenous 
substances contained in leaf and stem in the form of 
pasture, forage or hay, rather than the matured grain. 
Hence, nitrogen, which promotes this form of growth, 
is an important constituent, and under any conditions 
there should be a liberal supply provided. 

The clovers, on the other hand, are not perennial, 
with the partial exception of "white" or "Dutch" 
clover, and with this exception they all possess a tap- 
root, which penetrates downward, and as it descends, 
throws out fibrous roots into the various layers of 
soil. They are capable of readily acquiring their 
mineral food, both because of their large root systems 
and because of the character of the roots. They, how- 
ever, differ in one very important particular from the 
cereals and grasses, in that under proper conditions, 
as already pointed out (p. 118), they are capable of 
acquiring their nitrogen from the air. Thus with 
liberal dressing of only phosphoric acid and potash, 
maximum crops may be secured. They are "nitrogen 
gatherers," and the tendency of their growth is to im- 
prove the soil for the nitrogen consumers, or for those 
that obtain their nitrogen only from soil sources. 

Root Crops 

Another class of plants, differing from those already 
described, includes the root crops, as beets, mangels, 



1,90 FERTILIZERS 

turnips and carrots. These plants cannot make ready- 
use of the insoluble mineral constituents of the soil. 
Hence, in order to insure full crops, they must be 
liberally supplied with available food. Of the three 
classes of fertilizing constituents, the phosphates are 
especially useful for turnips, while the slower -growing 
beets and carrots require that the nitrogen shall be in 
quickly available forms. The proper fertilization of 
sugar beets, for example, is of great importance, since 
not only is the yield affected by fertilization, but the 
quality of the beet for the production of sugar. 

White potatoes and sweet potatoes, the one a 
tuber, the other an enlarged root, constitute another 
class which does not possess strong foraging powers. 
They require their food in soluble and available forms, 
and with suitable soils potash is the ingredient that 
is especially useful in the manures applied. 

Market- garden Crops 

Another group of crops is distinguished as a class, 
not so much because of their peculiar habits of growth 
as because of the objects of their growth, though 
this latter fact has a very important bearing upon 
economical methods of fertilization. This class in- 
cludes what are called "market -garden crops," as 
lettuce, beets, asparagus, celery, turnips, cucumbers, 
melons, sweet corn, beans, peas, radishes, and various 
others. The particular object in raising these is to 
secure rapidity in growth, and thus to insure high 
quality, which is measured by the element of succu- 



FRUIT CROPS A DISTINCT CLASS 181 

lence. In order that this may be accomplished, they 
must be supplied with an abundance of available 
plant -food, and since nitrogen is the one element 
which more than any other encourages and stimulates 
leaf and stem growth, its use is especially beneficial 
to all of these crops. They must not lack for this 
element in any period of their growth, though, of 
course, a sufficiency of minerals must be supplied in 
order that the nitrogen may be properly utilized. 
Because of their high commercial value, the quantity 
of plant -food applied may be greatly in excess of that 
for any other of the groups, and profits, as a rule, are 
measured by this excess rather than by the proportion 
of the elements. 

Fruit Crops 

Another distinct class of crops, though differing 
materially in their individual characteristics, as well as 
in their time and period of growth, are the fruits. 
These differ from most other crops, in that a longer 
season of preparation is required, in which the growth 
may be so directed as to prepare the plant or tree for 
the proper development of a different kind of product, 
namely, fruit, as distinct from grain or seed in the 
cereals, or succulence in the vegetable crops. The 
fruit differs in its characteristics from the ordinary 
farm crops, in that its growth and development require 
a little different treatment, since it is necessary that 
there shall be a constant transfer of food from the 
tree to the fruit throughout the entire growing season. 
The growth of each succeeding year of tree and fruit 



182 FERTILIZERS 

is dependent, not altogether upon the food acquired 
during the year, but as well upon that acquired in the 
previous year, and which has been stored up in bud 
and branches. A knowledge of the habits of growth, 
the period of growth and the object of the growth of 
this class is, therefore, useful as a guide to the eco- 
nomical supply of the essential elements of growth. 
These crops must be provided with food that will en- 
courage a slow and continuous rather than a quick 
growth and development. 

SYSTEMS OP FERTILIZING SUGGESTED 

A careful review of the foregoing facts furnishes 
abundant evidence of the impracticability of attempts 
to give information concerning the use of fertilizers 
that will apply equally well under all of the conditions 
of farming that may occur. Nevertheless, there have 
been a number of methods or systems of fertilization 
suggested, each of which possesses one or more points 
of advantage. 

A System Based Upon the Specific Influence of a 
Single Element 

The one which has perhaps received the most atten- 
tion, doubtless largely because one of the first pre- 
sented, and in a very attractive manner, is the system 
advocated by the celebrated French scientist, George 
Ville. This system, while not to be depended upon 
absolutely, suggests lines of praetice which, under 



Sr STUMS OF FERTILIZING 183 

proper restrictions, may be of very great service. In 
brief, this method assumes that plants may be, so far 
as their fertilization is concerned, divided into three 
distinct groups. One group is specifically benefited by 
nitrogenous fertilization, the second by phosphatic, 
and the third by potassic. That is, in each class or 
group, one element more than any other rules or 
dominates the growth of that group, and hence each 
particular element should be applied in excess to the 
class of plants for which it is a dominant. In this 
system it is asserted that nitrogen is the dominant 
ingredient for wheat, rye, oats, barley, meadow grass, 
and beet crops. Phosphoric acid is the dominant fer- 
tilizer ingredient for turnips, Swedes, Indian corn 
(maize), sorghum and sugar cane; and potash is the 
dominant or ruling element for peas, beans, clover, 
vetches, flax and potatoes. It must not be understood 
that this system advocates only single elements, for the 
others are quite as important up to a certain point, 
beyond which they do not exercise a controlling 
influence in the manures for the crops of the three 
classes. This special or dominating element is used in 
greater proportion than the others, and if soils are in 
a high state of cultivation, or have been manured with 
natural products, as stable manure, they may be used- 
singly to force a maximum growth of the crop. Thus,. 
a specific fertilization is arranged for the various: 
rotations, the crop receiving that which is the most 
useful. There is no doubt that there is a good scien- 
tific basis for this system, and that it will work well, 
particularly where there is a reasonable abundance 



184 FERTILIZERS 

of all of the plant -food constituents, and where the 
mechanical and physical qualities of soil are good, 
though its best use is in "intensive" systems of prac- 
tice. It cannot be depended upon to give good results 
where the land is naturally poor, or run down, and 
where the physical character also needs improvement. 

A System Based Upon the Necessity of an Abundant 
Supply of the Minerals 

Another system which has been urged, notably by 
German scientists, is based upon the fact that the 
mineral constituents, phosphoric acid and potash, 
form fixed compounds in the soil, and are, therefore, 
not likely to be leached out, provided the land is con- 
tinuously cropped. They remain in the soil until used 
by growing plants, while the nitrogen, on the other 
hand, since it forms no fixed compounds and is 
perfectly soluble when in a form useful to plants, 
is liable to loss from leaching. Furthermore, the 
mineral elements are relatively cheap, while the nitro- 
gen is relatively expensive, and thus that the eco- 
nomical use of this expensive element, nitrogen, is 
dependent to a large degree upon the abundance of 
the mineral elements in the soil. It is, therefore, 
advocated that for all crops and for all soils that are 
in a good state of cultivation, a reasonable excess of 
phosphoric acid and potash shall be applied, sufficient 
to more than satisfy the maximum needs of any crop, 
and that the nitrogen be applied in active forms, as 
nitrate or ammonia, and in such quantities and at 



MINERAL SUPPLIES ADVANTAGEOUS 185 

such times as will insure the minimum loss of the 
element and the maximum development of the plant. 
The supply of the mineral elements may be drawn 
from the cheaper materials, as ground bone, tankage, 
ground phosphates and iron phosphates, as their 
tendency is to improve in character; potash may come 
from the crude salts. Nitrogen should be applied 
chiefly as nitrate of soda, because in this form it is 
immediately useful, and thus may be applied in frac- 
tional amounts, and at such times as to best meet 
the needs of the plant at its different stages of 
growth, with a reasonable certainty of a maximum 
use by the plants. Thus no unknown conditions of 
availability are involved, and when the nitrogen is so 
applied, the danger of loss by leaching, which would 
exist if it were all applied at one time, is obviated. 

This method also possesses many advantages, par- 
ticularly where the "intensive" system is practiced, 
though it is also useful in quickly building up worn- 
out soils, or those naturally poor, because in any case 
these must be provided with liberal supplies of the 
minerals, and when these only are applied, the im- 
mediate outlaj- is far less than if the expensive ele- 
ment, nitrogen, were included; and a greater economy 
in the use of nitrogen is accomplished if it is added 
in small amounts when required. Besides, in the im- 
provement of soils, the liberal application of the 
minerals is conducive to an abundant growth of the 
legumes, which are able to acquire their nitrogen 
from the air, thus reducing to some extent the outlay 
for this expensive element. This system is strongly 



186 FERTILIZERS 

recommended where cheap phosphatic and potassic 
materials are readily accessible, as is the case in those 
countries where it is successfully used. 

A System Based on the Needs of the Plants for 

the Bifferent Elements as Shown by 

Chemical Analysis 

Another system of fertilization is based upon the 
theory that the different plants should be provided 
with the essential elements in the proportions in 
which they exist in the plants, as shown by chemical 
analysis. Different formulas are, therefore, recom- 
mended for each crop, the constituents of which are 
so proportioned as to meet its full needs. This 
method, if care is taken to supply an abundance of 
all the necessary constituents, may result in a com- 
plete though perhaps not an economical feeding of 
the plant, since it assumes that a plant which con- 
tains a larger amount of one constituent than of 
another requires more of that constituent in the fer- 
tilizer than of the others. It does not take into con- 
sideration the fact that the plant which contains a 
larger amount of one element than another may pos- 
sess a greater power of acquiring it than one which 
contains a smaller amount. 

Neither does this system take into consideration, 
as already pointed out (p. 178), that the period or 
time of growth of the plant also exercises a consider- 
able influence in indicating the capability of the plant 
to acquire its necessary food from the stores of the 



FERTILIZING POT-PLANTS 187 

soil, as may be illustrated by wheat and Indian corn, 
which both contain a relatively high content of 
nitrogen. Under good conditions of soil, wheat is 
specifically benefited by heavy dressings of quickly 
available nitrogen. Corn is not, and one reason is, 
that they possess different powers of acquiring food, 
due, to a considerable extent, to the difference in 
their time of growth, as well as to the period or time 
of their most rapid growth. 

This method may, however, be applied with very 
great advantage in greenhouse work, or in growing 
market -garden crops, where the amounts in the soil 
are not regarded as of importance, and excessive 
amounts of all are added. The system has been 
elaborated to a great degree of nicety for the grow- 
ing of greenhouse crops, flowers, and foliage plants, 
so much so that now artificial manure cartridges are 
prepared, which contain the amounts and kinds of 
food shown by the analysis of the different plants 
to be needed for their growth and full development. 
"The manure has the form of a fine powder, enclosed 
within a metallic wrapper, and firmly compressed into 
the shape of a cartouche or capsule, cylindrical in 
form, about three -fourths inch across and one -half 
inch in depth. It is simply thrust into the soil of 
the pot to a depth of one -half or one inch, and 
allowed to remain. After a time it is found that the 
fertilizer gradually disappears, and at length nothing 
is left but the little pill -box -like wrapper, which 
originally contained the mixed fertilizing powder."* 

•"The Gardener's Chronicle," London, England. 



188 FERTILIZERS 

A System in miieh the Fertilizer is Applied to the 
^^ Money Crop^^ in the Rotation 

Another system is also recommended, which is 
well adapted for "extensive" farming, where the ma- 
jority of crops which are grown in rotation possess 
a high fertility value and a low commercial value, 
and where one crop is regarded as the chief "money- 
maker." The system demands that to this crop shall 
be applied such an abundance of plant -food as to 
insure a continuous feeding, and a consequent max- 
imum production, even though adverse conditions 
intervene. Thus by a liberal supply of food, a money 
crop is secured which is as large as climate and sea- 
sonal conditions will permit, though which does not 
require all of the food applied. Hence the residue 
may be depended upon to fully nourish the remaining 
crops in the rotation, or at least the immediately suc- 
ceeding ones, thus saving direct outlay for them. 
This system may be illustrated as follows : 

On soils in good physical condition, and naturally 
well adapted for growing potatoes, this crop is se- 
lected as the "money-maker" in the rotation, which 
consists of corn, potatoes, wheat, clover and hay. 
The potato crop is fertilized so liberally, say with 
1,500 pounds per acre of a fertilizer containing — 

Nitrogon 4% 

Phosphoric at-id 6% 

Potash 1095> 

as to insure its maximum growth under average con- 
ditions. The removal of a large crop would still 



IRRATIONAL SYSTEM OF FERTILIZING 189 

leave a large residue of plant -food, which would pro- 
vide the following wheat crop with at least all of the 
mineral elements necessary to produce a maximum 
crop. If the wheat does not show vigorous growth in 
the spring, it is lightly top-dressed with nitrate of 
soda, which not only feeds it directly with nitrogen, 
but strengthens and invigorates the plant, enabling 
it to secure the minerals needed. The removal of a 
large crop still leaves an unused residue, upon which 
the clover crop following is also able to make a maxi- 
mum growth, and thus three crops are fertilized with 
the one application. The hay is either fertilized with 
both the minerals and nitrogen, or lightly top-dressed 
with nitrogen early in the spring. The yard manure, 
accumulated from the residue of straw, hay and corn, 
is applied to the corn, which, being a gross feeder, 
is able to obtain from this an abundance. Thus, by 
the heavy application of fertilizer upon the "money 
crop," all the crops in the rotation are benefited. 

This method possesses many valuable features, and 
is, perhaps, quite as well adapted as any other for this 
system of farm practice. 

An Irrational System 

The most expensive and irrational system of all, 
and one more commonly practiced than any other in 
general farming, may be termed the "hit or miss" 
system; if a "hit" is made, there is a profit, if a 
"miss," the loss is trifling. In this system, no special 
thought is given to the character of the crop or its 



190 FERTILIZERS 

needs. If the farmer can afford it, he purchases a 
fertilizer, without regard to its composition, and ap- 
plies it in very small amounts. If it happens to con- 
tain that element which is particularly needed for the 
plant to which it is applied, a profit is secured. In 
too many cases, however, the constituents added are 
already in abundance in the soil, or so little of the 
fertilizer is used as to preclude any profit. 

SUMMARY 

With the exception of this last system, there are 
good features in all of these suggested methods of use, 
and it rests with the farmer to select the best points 
from each, or rather to use the suggestions in each 
which are in his judgment more applicable to his con- 
ditions. They are all based upon underhing principles, 
and pre -suppose a knowledge of them on the part of 
the farmer. They are, at best, but guides or sign -posts 
pointing toward better methods in the use of fertil- 
izers, rather than absolute rules to be blindly followed. 

The suggestions here and in subsequent chapters, 
in reference to the use of fertilizers, are formulated 
from the best information obtainable by the writer, 
and mainly from two sources : First, the results of 
experimental inquiry, and, second, the results of the 
observation and experience of practical men. In no 
case can absolute rules be laid down. Farmers may 
safely rely on the well-established principles, but each 
must remember that the use of the principles i^)nst 
be modified according to his own conditions. 



CHAPTER X 

FERTILIZERS FOR CEREALS AND GRASSES 

It has already been pointed out (p. 175) that 
these crops are classed as possessing a relatively low 
commercial value and a relatively high fertility value, 
and that, from a practical standpoint, in any fertiliza- 
tion of them a possible profitable return should be 
borne in mind. This is, of course, necessary in all 
cases, but is particulary neeessarj^ where an increased 
yield, as great as can be expected from an application 
of proper fertilizing materials, cannot possibly result 
in an extraordinary profit, a result quite possible with 
certain crops of the opposite class. The possible in- 
crease in yield, too is, dependent on the conditions of 
soil and season, and if these latter are such as to 
forbid a maximum increased yield, the immediate 
profits from the application are considerably reduced. 

It has been shown, too, by careful experiments, 
that, on the average, at least one- third of the nitro- 
gen applied to these crops, though contained in the 
best forms, is not secured in the crop, even under 
the most favorable conditions ; that is, in any case 
certain amounts are lost through drainage, the growth 
of weeds and denitrification ; and, further, that the 
minerals must exist in the soil, or must be supplied 
in suflBlcient excess, otherwise, the utilization of the 

(191) 



1 92 FERTILIZERS 

nitrogen by the plant is still further reduced. The 
expense of fertilizer per unit of increase in these 
crops is, therefore, relatively greater, even under the 
best conditions of its use, A bushel of wheat, with 
its accompanying straw, will contain, for example: 

Nitrogen 1% lbs. 

Phosphoric acid % *' 

Potash IX " 

It will be observed that the amounts of fertilizer 
ingredients contained in the crop are such that, if the 
seasonal conditions are perfect, so that the maximum 
of the amounts applied are recovered in the crop, the 
cost of fertilizers per bushel of increase is still rela- 
tively high, thus showing that great care must be 
exercised in order that a direct and immediate profit 
may be secured. Nevertheless, since the cost of pre- 
paring the land and of harvesting the crop is but 
slightly greater for a large crop than for a small one, 
the larger returns for the labor very frequently pay 
well for the application of the material, even though 
the margin of money profit is small. In crops of 
this sort therefore, and especially when grown on 
the "extensive" plan, an important point to be de- 
termined is whether the land is deficient in all of 
the constituents for grain and hay growing, or whether 
only one or two are lacking, in order that in the ap- 
plications made, only those constituents are supplied 
that are necessary, and adding to an excess already 
present is thus avoided, with a consequent saving in 
the cost of the fertilizer. 



FARMERS SHOULD EXPERIMENT 193 

EXPERIMENTS TO DETERMINE THE LACKING 
ELEMENT 

The lacking element cannot be fully determined, 
except by direct experiments by the farmer himself. 
That is, uo general principle can be depended on 
as an absolute guide. He should learn whether his 
soil is deficient in any of the elements, and, if so, 
which ones should be applied to the different crops 
in his rotation. A careful study along this line, too, 
will show whether it is fertilization that is required 
to meet seeming deficiencies, for it frequently hap- 
pens that the needs of the soil are not so much for 
added plant -food as for better management of the 
soil in other respects, in order that natural supplies 
may be made more available. 

It may seem, at first glance, that experimenting 
should be left to the experiment stations, and that 
farmers should be advised by them in respect to the 
needs of their soils in respect to plant -food. This 
is partly true, but the proper function of experiment 
stations is to establish principles, the application of 
which must be left, in large part at least, to the 
intelligence of those who are to utilize them. The 
farmer must study his own conditions. Scientific in- 
quiry has established the facts that soils differ in their 
content of the different plant -food elements, and that 
those of practically the same chemical composition 
differ in respect to their physical qualities, both of 
which conditions exercise an important influenoe upon 
the availability of the constituents. 

M 



194 FERTILIZERS 

This experinfenting may also seem to be a trouble- 
some operation, yet, if thoughtfully managed, it will 
mean but little extra labor, and the resulting gain 
may be far in excess of the cost of the work. For 
example, if it is shown that fertilization under certain 
conditions is not the thing needed, and, therefore, not 
profitable, it saves possible outlay at once; if it shows 
that the application of certain of the constituents is 
a profitable practice, it enables the adoption of a 
systematic scheme of fertilization. 

A Scheme for Plot Experiments 

The following simple scheme of plot experimenting 
has been suggested, and it admits of determining 
many of the points involved. This scheme includes 
ten plots, in which three are to be cropped without 
manure, as check plots, in order to show the produc- 
tive capacity of the uumanured land. The plots may 
vary in size, though it is desirable that they should 
"contain at least one -twentieth of an acre, and that 
they should be long and narrow, in order to include 
as many inequalities of the soil as possible, though 
in any case land as uniform as possible in physical 
and chemical qualities, and fairly representative, 
should be selected. The following plan permits of a 
study of the effect of the application of individual 
constituents, and of their various combinations. If 
desired, in order to simplify the work in the begin- 
ning, only the first four plots need be taken. This 
will reduce the labor, and, at the same time, permit 



PLAN OF JSXPERIMENTS 195 

a study of the soil's deficieucies iu respect to single 
elements of plant -food, and the relative needs of 
the different crops for the various constituents. 

Plan of Experiments — Size of Plots, -^ of an Acre 

Plot I. Check. No fertilizer. 

II. Nitrate of soda 8 lbs. 

III. Superphosphate 16 " 

IV. Muriate of potash 8 " 

V. Check. No fertilizer. 

VI. Nitrate of soda, 20 lbs. Superphosphate, IG " 

VII. Nitrate of soda, 20 " Potash 8 " 

VIII. Phoshoric acid, 40 " Potash 8 " 

IX. Nitrate of soda, 8 " Superphosphate, 16 " 

Potash 8 " 

" X. Cheek, No fertilizer. 

The rate of application per acre is greater than 
would naturally obtain in practice, in order both to 
facilitate the distribution of the fertilizer, to furnish 
a sufficient abundance of the constituent, and to pro- 
vide against unfavorable conditions. 

Preferabl}', the application should be made broad- 
cast, and before planting, if an uncultivable crop, 
though for cultivable crops it may be applied later 
and harrowed in. 

It will be observed that the amounts of fertilizer 
are one pound per square rod, or multiple thereof. 
Thus, in order to insure an equal distribution over 
the entire area, it may be roughly divided into plots 
of a square rod, and the required material for each 
rod applied separately. Careful weights should be 
made of the yields of the different plots, as a basis 



196 FERTILIZERS 

of comparison. The same fertilizers should be used 
on the different crops of the rotations, and, as inter- 
est is increased in the work, different forms and 
amounts of the various constituents may be intro- 
duced. 

Results That May Be Attained 

If it is found that for a certain crop only one of 
the applied constituents profitably increases the yield, 
then that should be used until the need of the others 
is apparent. If two are needed to accomplish the 
results, use two, and so on; though in the long run, 
or as the practice approaches the "intensive" system, 
all will doubtless be required. In "extensive" farming 
this is a very desirable line of experimentation, and 
can be carried out by individual farmers. It is useful 
not only in showing the deficiencies of the soil for 
the various crops, but is educative in its character, as 
it familiarizes the farmer with the materials that are 
used in making fertilizers, and encourages exact 
methods of work. Since, as already' stated, the need 
very frequently is not so much for added fertility as 
it is for better preparation and cultivation of the soil, 
or for amendments such as lime, it Avould be a desir- 
able practice to include in the number of plots here 
indicated one or two in which the cultivation of the 
soil was made more perfect, in order to determine 
whether the need is for more fertility elements or 
whether it is for better tillage, the effect of which 
is to render more of the soil constituents available to 



THE RESULTS OF EXPERIMENTS 197 

the plant. One or two to which lime is added may- 
be advisable, in order to determine whether this sub- 
stance is needed either to correct acidity or to make 
available otherwise unusable compounds. This method, 
while particularlj^ desirable where " extensive " methods 
of practice prevail, is of less importance where the aim 
is to grow maximum crops, in which case both the 
crop and its rotation are to be considered, and the 
needs of the plant rather than the deficiencies of 
the soil require first attention. 

The results of experiments which have been eon- 
ducted with great care in a number of states show 
that where "extensive" methods are practiced certain 
elements need not be added in the fertilizers; that 
is, that the soil contains such an abundance of them 
that the plant is able to obtain a full supply, at least, 
for a long time. For example, it has been shown 
that on the chief sugar -producing soils of Louisiana 
and Mississippi, and the cotton soils of Georgia and 
Texas, the addition of potash has been of less im- 
portance in the past than the other elements, and it 
frequently does not need to be included in the fer- 
tilizer, while phosphoric acid is always needed. 

The results of field experiments on this plan in 
New Jersey, on reasonably good, loamy soils, indi- 
cate that phosphoric acid and potash are of much 
more importance in fertilizers for corn than nitro- 
gen, whereas upon sandy soils, nitrogen and potash 
are of relatively more importance than phosphoric 
acid; that is, even where "extensive" practice is used 
there are conditions where one or more of the ele- 



198 FERTILIZERS 

ments are not required iu order to secure maximum 
crops, which eliminates the necessity for an imme- 
diate outlay for those constituents that are not 
lacking. Where experiments of this sort have not 
been carried out and the specific needs determined, it 
becomes nece.s.sary to assume that all of the constituents 
are required, and to apply the amounts and propor- 
tions of those which the general considerations of the 
soil, season, climate and crop would seem to demand. 

As already pointed out, the methods of fertilization 
here suggested, though in many instances apparently 
positive, are not to be interpreted as absolute rules, but 
rather used as guides, based upon the best information 
that it has been possible to obtain, both as a result 
of scientific inquiry and of practical experience. 

THE IMPORTANCE OF SYSTEM IN THE USE OF 
FERTILIZERS 

The following rotation is assumed, in order to show 
the necessity of a definite system of work, which is 
quite as important iu this branch of farming as in 
many others in which system is apparently 'more 
essential, — though in fact it is quite as necessary to 
observe a definite system in the feeding of plants as 
in the feeding of animals with the plants : 

Illustration ok a Rotation 

First year Maize (corn). 

Second year Oats. 

Third year . . . . ' Wheat. 

Fourth year Clover and timothy 

Fifth year Timothy hay. 



SYSTEMATIC FEBTILIZATION 199 

Indian Corn Exhaustive of the Fertility Elements 

Since in rotations of this sort a fair number of live 
stock is usually kept, a considerable amount of ma- 
nure is made, which should be carefully cared for and 
used, as it contributes materially to the success of the 
plan. The manure may be used in part on land for 
corn, and should be spread broadcast, practically as 
fast as made during the fall, winter and early spring. 
This plant, because it is a gross feeder, and also 
because it makes most of its growth during the sum- 
mer season, when activities in the soil are most rapid, 
is able to appropriate from the coarse manures a larger 
proportion of the constituents than would be possible 
for crops which make their greatest growth earlier or 
later in the season. In the summer, too, the condi- 
tions are most favorable for nitrification, and soils 
which possess a fair content of vegetable matter are 
usually able to furnish the nitrogen needed in addition 
to that supplied in the organic manures, particularly 
in the middle and southern states. The considerable 
amounts of potash required for the growth of stalks, 
and the phosplioric acid for the formation of grain, 
demand that a liberal suppl}' of these constituents be 
provided, and the fertilizer for the corn should, there- 
fore, contain an abundance of available phosphoric 
acid and of potash. 

A crop of 50 bushels of shelled corn per acre, with 
the accompanying stalks, will remove, on the average, 
80 pounds of nitrogen, 29 pounds of phosphoric acid, 
and 55 of potash. It is an exhaustive crop. A fer- 



200 FERTILIZERS 

tilizer, therefore, tliat would furnish 30 pounds of 
phosphoric acid and 40 of potash would be regarded 
as a fair dressing for land of medium quality. A part 
of the phosphoric acid, at least, should be in a soluble 
form, in order to supply the early needs of the crop. 
The remainder may consist of ground bone or tankage, 
if the phosphoric acid in these can be obtained more 
cheaply, since they will decay rapidly enough to supply 
the demands for the later growth. The potash may be 
either muriate of potash or kainit, though the former 
is preferable if it is applied in the drill, which is, if 
used in these amounts, a perfectly safe practice so far 
as injury to the plant is concerned; though fertilizers 
containing large amounts of potash salts are preferably 
applied broadcast on raw ground of a clayey nature, 
and well worked into the soil, thus insuring a good 
distribution. The cost of an application of this sort 
will be relatively small, and the minerals added will be 
more than sufficient to provide for a consideral)le 
increase in crop. If the land is light and sandy, 
nitrogen should be added, even though it has received 
a good dressing of yard manure, as these lands are 
usually deficient in this element, and organic forms are 
usually quite as useful as the soluble nitrate or 
ammonia, since the seasonal conditions during the 
period of growth are favorable for the rapid change of 
the nitrogen in materials of good quality, like blood, 
concentrated tankage, or cotton-seed meal, into nitrates. 
The amounts of nitrogen needed would, under ordinary 
conditions, be supplied by 100 pounds of high-grade 
blood, or 200 pounds of cotton-seed meal. The nitro- 



FERTILIZERS FOR CEREALS 201 

gen may also be obtained by substituting tankage for 
the superphosphate, though it is not so desirable a 
practice. 

In this matter of fertilizing, it must be remembered 
that weeds appropriate plant -food quite as readily as 
the corn, wherefore in order to obtain the best results 
from the fertilizers added, clean cultivation should be 
practiced. 

Oats 

For the oat crop that follows corn, and which makes 
its best growth early in the season, before nitrification 
is rapid, quickly available forms of nitrogen are very 
desirable ; and inasmuch as the oats require an abun- 
dauce of phosphates, a fertilization with phosphoric 
acid is also essential. Hence, fertilizers consisting of 
mixtures of nitrate of soda and superphosphates have 
proved of great value for this crop. If mixed at 
home, they should be applied immediately after prepa- 
ration, for a loss of nitrogen may result if the mix- 
ture is allowed to stand for anj^ length of time. An 
application of 8 pounds of nitrogen and 18 of phos- 
phoric acid, or 200 pounds per acre of a mixture of 50 
pounds of nitrate of soda and 150 of acid phosphate, 
has proved quite as profitable on medium soils as 
heavier applications, mainly because the oat crop is 
a less certain one than corn ; besides, it frequently 
suffers severe losses in harvesting, which increase the 
risk from an expensive fertilization. The application 
of potash is not so necessary if added in the fertil- 
izer for corn, as suggested, except on light, sandy soils. 



202 FERTILIZERS 

Wheat 

For the wheat crop following oats, the rest of the 
farm manure on hand may be applied after plowing, 
well harrowed into the surface soil, and a fertilizer ap- 
plied which shall be rich in available i)hosphoric acid, 
and which shall contain only a sufiQcient amount of 
nitrogen in quickly available forms to insure a good 
fall growth. When the laud has been well fertilized 
for previous crops, a dissolved animal bone super- 
phosphate is an excellent fertilizer for wheat, because 
containing the elements, phosphoric acid and nitrogen, 
in good forms and proportions. If more nitrogen is 
needed than is provided by 200 to 300 pounds of this 
fertilizer in order to mature the crop, which is fre- 
quently the case, particularly if the winter has been 
severe, or if the land is light, it may be applied in the 
spring, and preferably in the form of a nitrate, which 
distributes readily, and is immediately available, ad- 
vantages not possessed by other forms. At this period 
of its growth, the crops need to make a rapid appro- 
priation of nitrogenous food, though the conditions are 
not yet favorable for the change of nitrogenous organic 
compounds in the soil into the available nitrate. The 
top -dressings should be made as soon as the crop has 
been well started, and should range from 75 to 150 
pounds per acre, according to the character of the 
soil and previous fertilization. The better the natural 
character of the soil and its treatment, the larger the 
dressing that may be applied with possible profit, 
though in no case should it exceed the larger amount. 



FERTILIZERS FOR CLOVER AND TIMOTHY 203 

Clover 

For the clover which follows the wheat, only the 
minerals, phosphoric acid and potash, need be applied. 
An increased return is likely to follow such an 
application, as the clover is not able to utilize to the 
fullest extent the nitrogen from the air except when the 
soil is supplied with an abundance of mineral food. 
An application which will furnish 12 pounds of phos- 
phoric acid and 25 pounds of potash per acre marks 
the minimum dressing, and it may be applied with 
advantage immediately after the wheat is harvested. 

Timothy 

The timothy, the next crop in the rotation, is a 
member of the grass family, and is especially benefited 
by nitrogenous fertilization, and top -dressings in the 
spring with nitrate of soda have proved of great value 
on soils well supplied with minerals, though experienced 
farmers have learned that better results are obtained if 
the minerals are applied with the nitrate, thus in- 
suring a better growth and development of plant. A 
mixture made up of 150 pounds of nitrate of soda, 
100 of acid phosphate and 50 of muriate of potash, at 
the rate of 300 pounds per acre, is now used by many 
successful hay growers. The application should be 
made as soon as the crop has well started in the 
spring. 

The system of fertilization here outlined is not to be 
advocated except under circumstances where it is not 



204 FERTILIZERS 

possible or practicable to supply such an abundance of 
plant -food as will guarantee a maximum production, as 
in "intensive" practice, in which the yield is measured 
by climatic and seasonal rather than soil conditions, 
but rather such additions as will return a profit and at 
the same time tend toward the improvement of soil. 
This system is economical in the use of nitrogen, the 
most expensive element. It provides a sufficient 
amount of available plant -food to insure a reasonable 
increase in crop, and it is well adapted to lead the 
farmer \iy easy steps from the "extensive" to the 
"intensive" system of farming. 

A Gain of Fertilifi/ hy the Boiation System 

Assuming that tlie increased yield of corn is 20 
bushels, with accompanying stalks, of wheat 10 bushels 
per acre, of oats 15 bushels, of clover % ton, and of 
timothy % ton, the amounts applied will be practically 
sufficient to furnish all of the potash contained in this 
increase, and more than sufficient to meet the demands 
for phosphoric acid. That is, by this system, there has 
been applied in the materials 30 pounds of nitrogen, 
64 of phosphoric acid and 80 of potash. While, if 
this increased crop was secured, the following amounts 
would be required : 71 pounds of nit"ogen, 31 of 
phosphoric acid and 79 of potash. The considerable 
amounts of plant -food contained in the yard manure, 
and the gain from the roots and stubble of the clover, 
serve to supply the balance of nitrogen required, and 
to provide a store of unused residue for future crops. 



NECESSITY OF AN EXCESS OF FOOD 205 

The method, if adopted, would be more rational, and 
likely to result in more satisfactory returns than the 
one now generally practiced, namely, to purchase with- 
out particular regard to the character of the materials 
furnishing the constituents, or their proportions, and 
to apply, on the average, even less per acre than is 
here recommended. Assuming that 200 pounds per 
acre of the average corn fertilizer, showing a composi- 
tion of 2.5 per cent nitrogen, 8 of phosphoric acid and 
5 of potash, were applied only to the crops corn, oats 
and wheat, omitting both clover and timothy, there 
would have been added 15 pounds of nitrogen, 48 of 
phosphoric acid and 30 of potash, amounts of each too 
small to provide for a large increase in crop, provided 
all were needed. 

The Necessity of Adding More Plant -food tJian is 
Required by <i Definite Increase in Croj) 

It may be asked, why add more of the constituents 
than is necessary to provide for a definite increase in 
crop? Assuming that the avei-age yield of the land 
is twenty bushels of wheat per acre, and the aim is 
to secure thirty bushels, why not add the constituents 
in the amounts and proportions necessary to provide 
for this extra increased yield, rather than any 
excess of these amounts? The answer is, that in 
order that such a result may be accomplished, the 
conditions would need to be absolutely perfect, so 
that the plant would have at its command the amount 
of food needed each day. If a period in the growth 



206 FERTILIZERS 

of the plant should be so wet or so dry as to prevent 
the plants from acquiring the food necessary for their 
continuous growth, there would be no opportunity for 
them to gather food faster, when the better conditions 
followed the unfavorable conditions, and thus to over- 
come the ill effects of the period of partial starvation. 
In other words, if there were only sufficient food to 
supply the plant under normal conditions of season, 
the plant, after a period of time during which there was 
no growth, could not grow faster than it did before, 
hence it could not catch up in its growth and make a 
full crop. Furthermore, the plan of applying only 
that needed for the increase must necessarily assume 
that the plant -food is in the best forms, and that the 
phj'sical conditions of soil are so perfect as to cause 
it to absorb and retain all the food applied, and in 
such a manner as to permit it to be readily obtained 
by the plant. A further advantage is to enable the 
clover i^lant in the rotation to fully exercise its power 
of acquiring nitrogen from the air. Moreover, if 
properly carried out, it fulfils the idea of successful 
agriculture ; viz., the production of profitable crops, 
while at the same time not reducing, but increasing, 
the potential fertility of the soil. 

.The System Should Be Modified if no Farm Manures 
are Used 

In this rotation, if no manures are available, as 
indicated, then the amounts and kinds of fertilizers 
should be somewhat changed. For example, if it was 



EXCLUSIVE USE OF FEBTILIZEBS 207 

necessary to supply the corn crop with a sufficient 
abundance of all the elements in artificial forms, then 
the proportions of nitrogen should be somewhat greater 
and the total amounts of the constituents applied to 
the different crops considerably increased. For corn, a 
mixture consisting of 20 pounds of nitrogen, 30 of 
phosphoric acid and 50 of potash should be applied, 
and if grown upon raw ground rather than upon sod, 
it would be desirable to still further increase the 
nitrogen. The oats could be fertilized, as before rec- 
ommended, while the wheat should have an increased 
supply of both nitrogen and phosphoric acid, — double 
the amounts recommended when used with manure,— 
besides an addition of at least 10 pounds per acre of 
potash. The fertilizing of the clover and timothy need 
not be changed. If, in a rotation of this character, 
barley were substituted for oats and rye for wheat, the 
fertilization need not be materially changed, though the 
rye possesses a slightly greater power of acquiring 
phosphoric acid than wheat, and the nitrogenous top- 
dressings may be omitted, unless the crop is grown 
primarily for straw rather than for grain. The barley 
is also less able to acquire its phosphoric acid than 
the oats, and is especially benefited by nitrogen, though 
care should be exercised to regulate the amounts ap- 
plied in order to prevent lodging, which affects both 
the yield and quality of the grain. If in the rota- 
tion the timothy hay is omitted, then the fertilization 
for the corn may be reduced, as on good soils the 
yard manure, together with the plant -food stored in 
the surface in the clover sod, will furnish an abundance. 



208 FERTILIZERS 

FERTILIZERS FOR A SINGLE CROP GROWN 
CONTINUOUSLY 

When it. is desirable to grow any one or all of 
these crops continuously (and this practice may be 
followed with advantage, particularly when a legumi- 
nous catch -crop is seeded with the main crop, which 
insures a continuous occupation of the land and also 
provides vegetable matter and nitrogen), the fertiliza- 
tion would naturally be somewhat different, and, as a 
rule, would require more nearly even quantities of the 
different constituents. For corn, a fertilizer supplying 
20 pounds of nitrogen, 40 each of phosphoric acid and 
potash, would provide for a liberal increase in the 
yield from year to year. The nitrogen should prefera- 
bly be in good organic forms, which would decay rap- 
idly enough to supply the needed available nitrogen 
during the growing season. The i)hosphoric acid may 
be drawn partly from superphosphates and partly from 
organic compounds, as ground bone and tankage, pro- 
vided these latter may be secured at as low a price as 
the superphosphate, and the potash applied in the 
form of a muriate or kainit. Fertilizers may be applied 
broadcast and well harrowed into the soil, or part may 
be distributed in the row at time of planting. 

If a catch crop were seeded to be used as green 
manure, as, for example, crimson clover, the applica- 
tion of nitrogen may be very materially reduced. This 
practice has been followed with advantage in the middle 
and southern states. 

For continuous wheat growing, a fertilizer may be 



FERTILIZERS FOR A CONTINUOUS CROP 209 

used at time of seeding wliieh supplies 10 pounds of 
nitrogen, 40 of phosphoric acid and 20 of potash. A 
small part of this nitrogen would better be in the form 
of a nitrate, which will encourage a good top -growth 
in the fall, as well as a deep root system ; the phos- 
phoric acid should be soluble, in order to supply the 
immediate needs of the young plant, and the potash 
in the form of a muriate. Such an application would 
provide for a very considerable increase in crop, par- 
ticularly if followed in the spring by a top-dressing of 
100 pounds per acre of nitrate of soda. 

The top-dressing with nitrate of soda is, however, 
not always advisable. The chief objection to its use is 
that it does not encourage, but frequently seems to 
retard, the growth of clover, though its very great 
advantage is that it encourages the deeper rooting of 
the wheat and the more rapid growth of grasses. If 
continuous cropping of wheat is practiced, clover 
should be seeded with it, in order that the ground 
may be constantly occupied, and thus prevent leaching, 
as well as mechanical losses of fertility, and also to 
supply vegetable matter containing nitrogen for the 
succeeding crop. When a system thus outlined has 
been continued for a few years, the nitrogen in the 
fertilizer may be largely omitted. 

The same considerations apply to rye as were in- 
dicated for wheat. Oats are seldom grown as a 
continuous crop, though if it should be desirable, a 
fertilizer furnishing at least 20 pounds of nitrogen, 
25 of phosphoric acid and 10 of potash would be a 
good dressing, care being taken that a large portion 



210 FERTILIZERS 

of the nitrogen exists as nitrate or as ammonia, in 
order to stimulate and strengthen the early growth of 
the plant. For the grass crop, or continuous mowing 
land, a fertilizer rich in nitrogen and potash should be 
applied. A good application in the spring may consist 
of 25 pounds of nitrogen, 15 of phosphoric acid and 
25 of potash, and immediately after the hay is har- 
vested a further application of at least 20 pounds of 
nitrogen and 30 each of phosphoric acid and potash 
should be applied. The nitrogen in this ease may 
consist partly of organic forms, though the soluble 
nitrogen is to be preferred as top -dressings where it 
can be procured at such a price as to make it compara- 
ble with other forms. The nitrogen of bone, tankage 
and other slower -acting forms is excellent for the 
grasses, though these should be preferably applied and 
well worked into the soil previous to seeding. The 
early spring application should consist largely of solu- 
ble nitrogen, both to encourage a rapid appropriation 
of this element by the plant early in the season, as 
well as a deeper root -system, and consequently a 
greater di'ought- resisting power, and also to provide the 
elements necessary for the increased crop. The sum- 
mer or later application stimulates and strengthens the 
roots for the coming season. If an aftermath crop is 
removed, or if it is pastured, a further application 
may be made, which may consist largelj' of the mineral 
elements. This fertilization of the hay' crop will also 
result in a richer product, for an abundant supply of 
nitrogen encourages a larger proportion of leaf growth, 
and consequently a smaller proportion of stem, contain- 



FERTILIZERS FOR MEADOWS 211 

ing the less valuable woody matter. Lands that are 
well fertilized in this way, if properly seeded in the 
first place, may make profitable mowing crops for a 
long series of years, and good crops cannot be expected 
unless liberal fertilization is practiced. 

Fertilizers for Meadotvs 

For meadows used as pastures, a more liberal 
application of the mineral elements is recommended, 
since an abundance of these encourage the growth of 
the clovers, which make a richer herbage than the 
grasses. Heavy nitrogenous fertilization is expensive, 
and encourages the growth of the grasses rather than 
the clovers. Pasturing, while less exhaustive than 
hay cropping, nevertheless results in the gradual 
depletion of fertility, and an abundant growth of 
rich pasturage can only be secured where there is an 
abundant supply of available plant -food. Mixtures 
made up of acid phosphate, ground bone and muriate 
of potash in equal proportions, make very good 
dressings, if applied in sufficient quantity, three hun- 
dred to five hundred pounds per acre annually. The 
ground bone is recommended because it decays 
slowly, and thus furnishes a continuous supply of 
nitrogen and of phosphoric acid. The application 
should preferably be made both in spring and in late 
summer, in order to secure a good growth, as well as 
to encourage the introduction of the clovers. In any 
system of continuous cropping, or in fact in any sys- 
tem of rotation -cropping, in which an abundance of 



212 FERTILIZERS 

organic matter is introduced in the way of green 
crops, or in decaying vegetable matter contained in 
roots, the land should occasionally receive a dressing 
of lime, both to supply that which the plants need, 
as well as to correct possible acidity of soil. 

WILL THIS SYSTEM of FERTILIZING PAY ? 

That fertilization will pay if carried out, as is 
pointed out here, and upon lauds not now producing 
paying crops, depends, of course, very largely upon 
the price of the crops, the cost of the materials, and 
the method of farming practiced. At the prices which 
have prevailed in the recent past, for both crops and 
fertilizing materials, there is no doubt that this 
reasonable fertilization, together with a good system 
of practice in other respects, — that, is, good plowing 
good harrowing, good drainage and good cultivation, 
— will result in very satisfactory returns. In fact, it 
has been shown by repeated experiments (see bulletins 
and reports of New Jersey Experiment Station) that 
the yields on land which is capable of producing an 
average crop of 15 bushels of wheat per acre, 30 of 
corn and 30 of oats, may be more than doubled by 
an abundant supply of fertilizing materials. Such an 
increase results in an actual direct gain, as well as 
in the saving of labor per unit of product, which is 
accomplished when the larger crop is secured. 

The main point in this whole matter of fertiliza- 
tion is to understand that a fertilizer is a fertilizer 
because of the kind and form of plant -food contained 



WILL FERTILIZING PAY? 213 

in it ; and that its best action, other things being 
equal, is accomplished when the soil possesses good 
physical qualities, when the management is also 
good, and when systematic methods are planned and 
adopted. "Hit or miss" fertilization, even for these 
crops, may pay, and doubtless, on the average does 
pay as well as some other things that farmers do, but 
does not pay as well as it might if better methods 
were used. 



CHAPTER XI 

POTATOES, SWEET POTATOES, TOMATOES AND 
SUGAR BEETS 

These crops differ from the cereals and grasses in 
that they are products of high commercial value, and 
are less exhaustive of plant -food constituents per unit 
of money value. As field crops they are usually grown 
in a rotation, and constitute one at least of the chief 
money crops. In sections near large markets these 
crops are, with the exception of sugar beets, divided 
into two classes, early and late, the early crop being 
regarded as the most profitable ; hence greater efforts 
are made, both in the way of fertilization and of 
management, to secure a large and early crop, than 
is the case with the late crop. For the early crop 
the natural supply of plant -food in the soil is not a 
prime consideration. In districts distant from markets, 
the late crop is the only one grown to any extent, and 
because it has the whole season for its growth, greater 
dependence is placed upon the natural resources of the 
soil. While, as already stated, these crops are not 
regarded as exhaustive of plant -food elements in the 
same sense as the cereal crops are, because it fre- 
quently happens that a bushel of potatoes, or of sweet 
potatoes, or of tomatoes, will bring as much as a 
bushel of corn, or sometimes as a bushel of wheat, 

. (214) 



FERTILIZERS FOR POTATOES 215 

yet the amount removed in the entire crop may be 
quite as great as in the grain crop, because of the 
much larger number of bushels grown per acre. 

FERTILIZERS FOR POTATOES, EARLY CROP 

It has been demonstrated, both by experiment and 
practical experience, that good crops of early potatoes 
require an abundance of plant -food, and that on soils 
of good character a heavy fertilization is usually more 
profitable than a medium or light application. 

The plant -food removed by a fair crop — 200 
bushels per acre of tubers — will, on the average, 
consist of 27 pounds of nitrogen, 12 pounds of 
phosphoric acid and 60 of potash. Even though 
the increase from the application of fertilizers is less 
than 100 bushels per acre, it is always advisable 
to add plant -food in considerable excess of these 
amounts : first, because the crop must be grown 
quickly ; and second, because a large part of its 
growth must be made in the early season, before the 
natural conditions are favorable for soil activities. 
A study of the fertility composition of the potato 
shows that of the three essential constituents, the 
potash is contained in the greatest amount and the 
nitrogen next, while the amount of phosphoric 
acid contained in it is comparatively small. Most 
fertilizer formulas for potatoes are, therefore, pre- 
pared with the idea of furnishing a greater amount 
of potash than of nitrogen or phosphoric acid. A 
study recently made by the Geneva Experiment 



216 FERTILIZERS 

Station* shows that the formulas prepared to con- 
tain the plant -food in nearly the proportions used 
by the entire potato plant, excepting that the phos- 
phoric acid is in considerable excess, were less useful 
than those containing very different proportions 
of the constituents, and which were based upon the 
experience of observing growers. That is, a formula 
of the first class, furnishing — 

Nitrogen 6% % 

Available phosphoric acid 5 % 

Potash 10% 

gave less satisfactory returns for the same amount 
applied than one furnishing — 

Nitrogen 4 % 

Available phosphoric acid S % 

Potash 10 %. 

This latter formula is very generally used in sections 
where early potatoes are an important crop. 

The Time and Method of Application 

These are matters of considerable importance. 
It has been urged, particularly by German experi- 
menters, that the potash salts, when used in such 
excess as seems desirable, should be applied more 
largely to the crop preceding, rather than directly to 
the potato crop. This method has not been adopted 
in this country to any extent, and it is believed that 



* Bulletin No. 137, N. Y. State Exp. Sta. 



THE AMOUNT OF FERTILIZER 217 

our climatic conditions are such as to cause a very 
general distribution of the salts throughout the soil, 
if applied, in part at least, just before planting and 
thoroughly distributed by cultivation. At any rate, 
very satisfactory returns are secured from the direct 
application to the crop of fertilizers of this composi- 
tion. In reference to the method of application, while 
very good results are secured from the application of 
the fertilizers directly in the row, this is to some 
extent influenced by the character of the soil. Where 
the soil is somewhat heavy, and the cii'culation of 
water is not perfectly free, it is less desirable than 
where the soils are open and porous, and free circu- 
lation is not impeded ; though where the amounts 
applied are considerable, it is recommended that at 
least one -half of the fertilizer should be applied 
broadcast and worked into the soil, and the remainder 
placed in the row at the time of planting. Naturally, 
when the soils are poor, a concentration of the con- 
stituents is more desirable than when the surround- 
ing soil possesses reasonably abundant supplies of 
available food. 

The Amount to be Applied 

As already stated, the amount of the different con- 
stituents to be applied should be in considerable excess 
of that required by the actual increase in crop, both 
for the reasons already given, and because it is 
desirable in crops of this sort to insure a continuous 
and abundant feeding of the plant. Where "intensive" 



218 FERTILIZERS 

practice is general, the amouuts applied very frequently 
reach a ton per acre of the high-grade fertilizer 
already mentioned, though the necessity for so large 
an application as this has been questioned, particularly 
if it is expected to give rise to a profitable return in 
the crop to which the application is made, and though 
it can be readily seen that if conditions should not be 
favorable the larger amounts would be preferable. The 
result of investigations of this point by the Geneva 
Experiment Station* showed that an addition of fer- 
tilizers above 1,000 pounds per acre, or 40 pounds of 
nitrogen, 80 of phosphoric acid and 100 of potash, 
was not as profitable as 1,000 pounds. It must be 
remembered, however, that these experiments were 
conducted upon light soils, and on these entire de- 
pendence must be placed upon added plant -food. 

In the best potato sections of New Jersey, the 
application of a fertilizer of this composition ranges 
from 1,000 to 2,000 pounds per acre, while the majority 
of the growers use the smaller rather than the greater 
quantity. Many use the larger, and are of the opinion 
that it is a profitable practice, because of the greater 
certainty of securing a good potato crop, and because 
the unused residue provides for large yields of the 
subsequent crop without further applications. The 
growers of potatoes in the vicinity of Norfolk, as 
well as farther south, also find it profitable to be 
generous in the use of fertilizer for this as well as 
for other crops of high commercial value. 



^Bulletins 93, 112, 137, N. Y. State Exp. St». 



FJSRTILIZEBS SHOULD BE A VAILABLE 219 

Form of the Constituents 

In the growing of potatoes, sulfate of potash is 
generally recommended in preference to the muriate, 
owing to the supposedly deleterious effect on the 
quality of the tubers resulting from the large quantities 
of chlorids contained in the muriate, though the dif- 
ferent forms, when properly applied, do not seem to 
materially influence the yield. That is, if muriate or 
kainit is applied previous to the planting of potatoes, 
the deleterious chlorids may be washed from the soil. 
There is no doubt that the sulfate improves the ap- 
pearance of the potatoes, making them more clean and 
uniform in size, though experiments that have been 
conducted do not show a material difference in the 
chemical composition of the tubers grown with any 
of the forms. The tendency on the part of the mu- 
riate seems to be to diminish the amount of dry 
matter, and inasmuch as the dry matter is mostly 
starch, the latter is thereby slightly reduced, though it 
has not yet been demonstrated that the good quality of 
the potatoes is measured by the content of starch.* 

In reference to the form of nitrogen, both theoret- 
ical considerations and the experience of growers con- 
firm the belief that for the early crop, a portion of 
the nitrogen should exist in the form of nitrate or 
ammonia and the remainder in quickly available 
organic forms, although no definite experiments have 
been conducted to determine this point, nor the one 

♦BuUetiu No. 137, N. Y. Stite (Geneva) Exp. Sta. Bulletin No. 80. N.J. 
£xp. SU. 



220 FERTILIZERS 

as to whether all of the nitrogen in the form of 
nitrate should be applied at the time of planting. A 
top-dressing after the potatoes have come up is a very 
desirable method of practice on light soils which have 
been liberally supplied with the minerals. 

On good potato soils, therefore, a good fertiliza- 
tion would consist of 800 pounds per acre, as a mini- 
mum, of a mixture containing : 

Nitrogen 3 to 4 % 

Phosphoric acJil 6 to 8 % 

Potash 8 to 10 % 

The nitrogen is to be in quickly available forms; 
the phosphoric acid, also, is to be available, and the 
potash to be derived from sulfate, particularly if fine 
quality of crop, as indicated by appearance, is desired. 
If only yield is considered, the muriate is quite as 
serviceable. 

LATE POTATOES 

For late potatoes, the considerations in reference 
to the form of the constituents and the amount of the 
application, as suggested for early potatoes, do not 
always hold good, since in many cases the crop is able 
to secure a larger proportion of its plant -food from 
soil sources, — due, first, to the longer period of growth 
of the plant, and second, to the fact that the crop is 
usually grown upon soils naturally richer in the 
plant -food elements, though the proportion of pot- 
ash, as in the formulas already indicated, should be 
relatively large. The nitrogen may be reduced, and 



FERTILIZERS FOR SWEET POTATOES 221 

the form of nitrogen may be derived largely from 
organic sources. Good formulas for late potatoes 
may consist of — 

Nitrogen 2%% 

Phosphoric acid :- 6 % 

Potash 8 % 

and the application may be from 600 to 800 pounds 
per acre. 

Where potatoes are grown in rotations with the 
cereal crops mentioned in Chapter X, the unused 
residue from the rather heavy application of fertil- 
izers to the potato crop is depended upon to very 
materially aid the growth of these, thus reducing the 
outlay for fertilizer for crops of a low commercial 
value. This practice is advantageous, though the 
prime object should be to feed the crop rather than 
the soil — that is, applj^ the fertilizer with the idea of 
securing a profit from it in the potato crop, rather 
than a possible profit in subsequent crops. 

SWEET POTATOES 

In the growing of sweet potatoes, the quality of 
the product is more important than in the case of the 
white potato. The northern markets distinctly recog- 
nize quality in this crop, and it is measured by size, 
shape, and results in cooking. The potato that brings 
the best price in the different markets is small, about 
the size of a white potato; in shape round, rather 
than oblong, and is di-y and mealy when cooked. 



222 FERTILIZERS 

This characteristic of the crop is influenced both 
by the character of the soil and of the manures and 
fertilizers applied. The soils best adapted are dry, 
sandy loams, and the most useful fertilizers are those 
which contain an abundance of minerals, — phosphoric 
acid and potash,— and not too large supplies of quickly 
available nitrogen. It is also true that the yields of 
sweet potatoes of this character are not as large as 
those that may be obtained when quality is not a 
prime consideration, and which are grown for the 
general market. 

Fertilizer Constituents Contained in an Average Crop 

This crop is very similar to the white potato in 
regard to food required. Two hundred bushels of 
sweet potatoes, not including vines, contain, on the 
average, 30 pounds of nitrogen, 10 of phosphoric acid 
and 45 of potash; and since the yield of the general 
crop is larger on the average than one of white 
potatoes, a liberal supply of the minerals must in 
all cases be provided. The studies made of this crop 
have not yet established the best proportions of the 
constituents in fertilizers, though such experiments 
as have been conducted show that those that contain 
a very considerable excess of potash over the other 
elements are preferable. While nitrogen is needed, 
too much, particularly in soluble forms, seems to 
encourage too large a growth of vine, which con- 
tributes to yield, but at the expense of quality, which 
is a very important consideration. The best growers 



PROFITABLE FERTILIZATION 223 

use fertilizers containing a small percentage of nitro- 
gen and a high percentage of phosphoric acid and 
potash. Applications that furnish 20 pounds of nitro- 
gen, 50 of phosphoric acid and 80 of potash per acre 
have given excellent results in regions in New Jersey 
in which market quality up to a certain point is quite 
as important as increase in yield, though, of course, 
yield is also considered. Any excess of nitrogen over 
this amount seems to contribute toward a larger, 
rather oblong, rooty growth of tuber, and to injure 
cooking quality. In growing crops for the general 
market, however, larger applications of nitrogen are 
demanded, and experiments have shown that organic 
forms are preferable to soluble forms, though the 
climate and season largely influence this point. In 
northern sections, and in cold seasons, the soluble 
forms are more useful than in the warmer climate 
and longer seasons of the South. 

There is no question, however, that commercial 
fertilizers can be depended upon to produce maximum 
crops of sweet potatoes, and at much smaller cost 
than with yard manure.* Results reported by the 
Georgia Experiment Station t indicate the following 
formula as an excellent one for sweet potatoes, 
though, as there stated, "the amounts that can be 
used vary considerably, depending upon the character 
of the soil — the richer the land in humus, the greater 
the quantity that can be safely used." "Thin soils 
will, of course, only stand very moderate manuring, 

* Bulletin P, New Jersey Exp. Sta. 
t Bulletin No. 25, Georgia Exp. Sta. 



224 FEB,TILIZE£i8 

and necessarily produce a very small yield." The 
formula consists of — 

Acid phosphate 320 lbs. 

Cotton-seed meal 360 " 

Kainit G40 " 

This formula will furnish about 25 pounds of nitro- 
gen, 50 of phosphoric acid and 80 of potash, and, 
according to the bulletin, will produce a yield of 
potatoes of from 200 to 400 bushels per acre, depend- 
ing upon the season and variety of potatoes planted. 
Experiments at the Georgia Station also show that 
organic nitrogen (cotton -seed meal) is preferable to 
nitrate of soda as a source of nitrogen. 

In making mixtures which furnish these propor-* 
tions of plant -food, other nitrogenous organic ma- 
terials, furnishing an equivalent of nitrogen, — as blood 
or concentrated tankage, — may be substituted for the 
cotton -seed meal, if they can be purchased c^uite as 
cheaply; and muriate of potash, furnishing an equiva- 
lent of potash, may be substituted for the kainit, if 
it can be more readily obtained. 

As already stated, however, this fertilizer is too 
rich in nitrogen for the production of the best quality 
of potatoes, as for example "Vineland Sweets," which 
command the highest prices in northern markets. The 
growers in that district use a fertilizer richer in the 
minerals ; one containing — 

Nitrogen 3 % 

Phosphoric acid 7 % 

Potash 12 % 



APPLICATION OF FERTILIZERS 225 

is very generally used, though reasonably heavy 
dressings of this are often further supplemented 
by applications of from 200 to 300 pounds of acid 
phosphate and 100 to 150 pounds of muriate of 
potash per acre. 

Tlie Applicafiou of the Fertilizers 

Owing to the fact that the sweet potato is grown 
from plants or slips, rather than from seed, and the 
fact that the best quality of potatoes is produced upon 
rather light, sandy land, it is desirable that the fer- 
tilizer should be applied some time before the putting 
out of the plants. The practice on this light land is 
to apply the fertilizer when making up the hills, which 
usually occurs from two to three weeks before the plants 
are set. That is, in making up the hills, the soil is 
ridged, and during the preparation of the ridge the 
fertilizer may be distributed in it and well mixed with 
the soil. Where the land contains more clay and 
humus it is frequently advocated that the potash 
manures be applied broadcast the previous year, and 
only the nitrogenous fertilizer and superphosphate be 
applied immediately to the plant. On soils of this 
latter character, this is doubtless the best system. If 
kainit, — which has been found to be preferable to mu- 
riate in the Georgia experiments referred to, — is used 
as the source of potash, it is very necessary that it be 
well mixed with the soil before setting out the plants. 
Heavy applications of this salt in the spring proved 
injurious in the experiments conducted at the New 



226 FERTILIZERS 

Jersey Station.^ The effect of fertilizers upon the 
chemical composition of the tuber was chiefly to reduce 
dry matter, and not apparently to affect edible quality, 
though the experiments were carried out upon the 
general crop rather than upon those grown for high 
quality. 

TOMATOES 

Tomatoes are largely grown as a field crop, and 
the object of their growth, whether for the early 
market or for the canneries, is a factor that must be 
considered in the adoption of systems of fertilization. 

'Field Experiments ivith Fertilizers for Tomatoes 

The impression is very prevalent among growers 
that the tomato does not require heavy manuring. 
Studies made at a number of experiment stationst 
show, however, that the tomato is a plant that quickly 
and profitably responds to the use of manures or ferti- 
lizers, and that the maturity and yield are very largely 
influenced by the method of manuring and fertilizing. 
Experiments were conducted by the New Jersey Station 
upon three farms located in different parts of the state, 
and during four seasons, the object of which was to 
test the effect on maturity and yield of the early crop 

* Bulletin P, New Jersey Experiment Station. 

t Bulletins Nos. 21 and 32, Cornell Experiment Station (Ithaca). Bulletin 
No. 17, Georgia Experiment Station. Annual Report for 1891, Maryland Experi- 
ment Station. Bulletin No. 11, Virginia Experiment Station. Bulletins Nos. 63, 
79 and O, and Report for 1892, New Jersey Experiment Station. 



THE NEW JERSEY EXPERIMENTS 227 

of the use of nitrate of soda in different quantities 
and at different times, both with and without the ad- 
dition of the mineral elements, phosphoric acid and 
potash, and to make a comparison of these with barn- 
yard manure. The results showed : 

First. That nitrate of soda was one of the best 
nitrogenous fertilizers for this crop, and that its use 
in small quantities (160 pounds per acre), or in large 
quantities (320 pounds per acre) in two applications, 
increased the yield materially, but not at the expense 
of maturity, and that this was equally true when used 
alone and when used in connection with phosphoric 
acid and potash. 

Second. That nitrate of soda, when used in large 
quantities (320 pounds per acre) in one application, in 
the presence of a sufficient excess of phosphoric acid 
and potash, did increase the yield, but at the expense 
of maturity. 

Third. That when properly used, nitrate of soda 
was a profitable fertilizer for the crop. 

It was shown, furthermore, that nitrate of soda was 
superior to both barnyard manure and mineral ferti- 
lizers alone, and on the whole, was but slightly less 
effective than the complete fertilizers. 

Fertilizers for the Early Crop for Different 
Conditions of Soil 

These results have been practically confirmed both 
by the experiments of the stations referred to, and 
also in actual practice on soils similar in character ; 



228 FERTILIZERS 

namely, those which were well adapted for the early 
tomato — light, well -drained sandy loams — and which 
had been previously well manured for crops entering 
the rotation. The results do not apply in the case of 
very poor soils, or upon heavy clay soils, which are 
not adapted for the early crop. 

The statement that it pays to fertilize early toma- 
toes, and that nitrate of soda is one of the best ferti- 
lizers for the crop, must, therefore, be accompanied by 
statements regarding the condition of soil and the 
purpose of growth. With the conditions clearly under- 
stood, a scheme of fertilization for early tomatoes may 
be outlined which, when the conditions are observed, 
will be likely to give much better results than methods 
of fertilization which do not take into consideration 
the habits of the plant and the special object of its 
growth. 

For example, on soils which have been well sup- 
plied with the mineral elements, phosphoric acid and 
potash, by previous manuring or fertilizing, a ferti- 
lizer very rich in nitrogen derived from nitrate of 
soda, or nitrate of soda alone, should be used ; the 
application at the time of setting the plant to be 
equivalent in nitrogen to from 80 to 100 pounds of 
nitrate of soda, with a second application of an equiv- 
alent amount made from three to four weeks later. 
A single application of the amount here suggested at 
the time of setting the plants would, perhaps, under 
good seasonal conditions give results quite as good, 
though the heavier application of nitrate at one time 
mny result, in certain cases, in the loss of nitrogen 



FERTILIZATION OF THE EARLY CROP 229 

by leaching, since it is an extremely soluble salt. In 
this ease a deficiency of food would result, and thus 
prevent the normal development of both plant and 
fruit. 

On soils which possess only good mechanical con- 
dition, and are very poor in plant -food, a heavier 
application of both nitrogen and the mineral elements 
will be required, in which case the following fertiliza- 
tion is recommended : 

Previous to setting the plants, or at the time they 
are set, apply 50 pounds per acre of phosphoric acid, 
preferably derived from superphosphate, and 100 
pounds of potash, derived from muriate, and thor- 
oughly harrow or cultivate into the soil ; and at 
the time of setting apply around the hill 100 to 150 
pounds per acre of nitrate of soda. Three to four 
weeks later, make another application of from 100 to 
150 pounds per acre of nitrate of soda. Owing to the 
small bulk of nitrate, it should be mixed with dry 
soil or sawdust, in order to insure even distribution. 
The only precaution to be observed is to prevent its 
immediate contact with the plant roots. If these 
methods are practiced, the plant secures its nitrogen 
in an immediately available form at a time when it 
is needed, — when it is set in the field. There is 
thus no delay in growth, and because of the presence 
of an abundance of the mineral elements no ex- 
cessive growth of vine is encouraged by the use of 
the nitrate, as would be the case were the mineral 
elements absent. Inasmuch as the nitrogen is ap- 
plied close to the plant, it is within the immediate 



230 FERTILIZKUS 

reach of its roots ; and because it is all in an im- 
mediately available form, which is used up rapidly, 
the tendency to late plant growth, which would be 
caused by a continuous supply of nitrogen, is not en- 
couraged, and a normal and rapid growth and de- 
velopment of fruit results. 

It is not stated that by this method of fertilization 
maturity is increased in the sense that the date of the 
first picking is earlier, but that a larger number of 
fruits is picked earlier. It was not shown in any of 
the experiments that the date of picking was made 
earlier by virtue of the nitrate, for, in fact, the 
earliest tomatoes were picked upon land where the 
minerals only had been applied. Here the yield was 
not satisfactory, but where the nitiarte was applied, 
because of the larger crop, a larger proportion of 
early tomatoes was secured. It is obvious that, in- 
asmuch as the price of the fruit rapidly declines as 
the season advances, receipts from the proportionately 
larger quantity of early fruit will be materially 
increased. 

The Use of Fertilizers with Yard Mamires 

When it is desirable to use yard manures with fer- 
tilizers for tomatoes, because of the abundance and 
cheapness of the former, they should be applied broad- 
cast, and the nitrate applied at the time of planting, as 
already described, rather than both together in the hill. 
The tendency in the latter case will be to cause a loss 
of nitrogen from the nitrate, depending upon the 



FERTILIZATION OF THE LATE CROP 231 

amount of organic matter in the manures. That is, 
experiments and experience have shown that under 
these circumstances more or less of the nitrogen in the 
nitrate may be lost. 

In the use of yard manures for early tomatoes, the 
application of excessive quantities should be avoided, 
as they are virtually nitrogenous manures, which, 
because of their organic character, feed the plant in 
proportion to their rate of decay. Hence, the presence 
of large quantities will encourage not only an undue 
growth of plant, but a late growth as well. The 
mineral fertilizers, as acid phosphate and muriate of 
potash, can be used with the yard manures with perfect 
safety, in fact, with great advantage, because supple- 
menting their proportionate lack of the mineral con- 
stituents. It is also desirable, where it is the practice 
to use manure, particularly if it is coarse, to spread it 
during the winter, in order that the soluble portions 
may become thoroughly distributed throughout the 
soil. As soon as the land is ready to work in the 
spring, it should again be plowed shallow and then 
deeply tilled, in order both to thoroughly warm up the 
soil, and to incorporate with it coarser portions of the 
manure. 

Fertilizers for Late Tomatoes 

In manuring and fertilizing for the late crop, the 
character of the crop and the season of its growth 
should be remembered. In the first place, the plants; 
for this crop are not put in the soil until summer, when 
the conditions are most favorable for the rapid change 



232 FERTILIZERS 

of organic forms of nitrogen into nitrates. Thus, if 
the soil has been manured or is naturally rich in vege- 
table matter, the additional application of nitrogen in 
immediately available forms is not so important. In 
the second place, the object of the growth is not early 
maturity, but the largest yield of matured fruit; hence 
it is more desirable to grow a larger plant than in the 
case of the early tomatoes. The fertilization should, 
therefore, be such as to furnish an abundance of all the 
elements of plant -food; and, inasmuch as the tomato 
belongs to the potash -consuming class of plants, any 
fertilization should be particularly rich in this element. 
It is not to be understood, however, that it is not 
necessary to apply nitrogen, for frequently soils are 
used that are either not well adapted for the plant or 
are poor, not having been previously well supplied with 
vegetable matter containing nitrogen. On such soils, 
additional applications are very important, and nitrate 
of soda is one of the best forms to use, as it is absorbed 
freely by the roots, encouraging an early and vigor- 
ous growth of plant and a normal development of 
fruit. Slow- acting organic forms of nitrogen, on the 
other hand, frequently begin to feed the plant and 
cause its rapid growth when the energies should be 
concentrated in the growth and maturity of fruit. 
Fertilizers that have proved very excellent are those 
which contain a relatively smaller amount of nitrogen 
than is required for early tomatoes, and are richer in 
phosphoric acid and potash. 

A study of the composition of both the fruit and 
vine of the tomato will serve to guide us in this 



COMPOSITION OF FBUIT AND VINE 233 

respect, though the amounts and proportions of food 
removed by any crop are not absolute guides, inas- 
much as the soil may furnish more of one constituent 
than another, and because the plant may have the 
power of acquiring certain of its constituents more 
readily than others. The analyses of the fruit and 
vines of tomatoes show that one ton contains : 

Nitrogen Phosphoric Acid Potash 
lbs. lbs. lbs. 

In fruit 3.20 1.00 5.40 

Vines (green) . . . 6.40 1.40 10.00 

Ten tons of the fruit, with the accompanying 
vines, which would probably reach four tons, would 
contain 57 pounds of nitrogen, 16 of phosphoric acid 
and 94 of potash. On a good soil, therefore, which 
without manure would produce five or six tons, 
there should be added a sufficient excess of the 
constituents to provide for a maximum production, 
and the materials should be relatively richer in nitro- 
gen and potash than in phosphoric acid. A mixed 
fertilizer composed of : 

Nitrate of soda 400 lbs. 

Bone tankage 700 " 

Acid phosphate 400 " 

Muriate of potash 500 " 

would contain, approximately, 95 pounds of nitrogen, 
144 of phosphoric acid and 250 of potash in each ton. 
An application of 500 pounds per acre of this mixture 
would furnish half as much nitrogen as is contained 
in a crop of ten tons, nearly as much immediately 
available phosphoric acid, and two -thirds as much 



'2,34 FERTILIZERS 

potash. Hence a dressing contaiuiug the amounts, 
kinds and proportions of plant -food here shown would 
be regarded as very desirable, since one -half of 
the nitrogen is in the form of a nitrate, which would 
contribute to the immediate growth of the plant. The 
amount of soluble and available phosphoric acid is 
sufficient to satisfy the needs of the crop throughout 
its entire growth, and such an abundance of potash 
as to contribute to the normal development of both 
plant and fruit. Formulas of this character have 
been used with good results, though the large pro- 
portion of salts sometimes make mixtures of this sort 
too moist to handle well, in which case a part of the 
potash, or even of the nitrate, may be applied 
separately with advantage. On poorer soils, the arti- 
ficial supply of plant -food should be proportionately 
greater, or sufficient to provide for the entire needs 
of a fair- sized crop, since as a rule the relative power 
of the plant to acquire food is somewhat slighter on 
poor soils than on good soils; or, stated in another 
way, the results from the use of fertilizers are pro- 
portionately better upon soils in good condition than 
upon those not well cared for. A good formula for 
these may consist of : 

Nitrate of soda 500 lbs. 

Bone tankage 500 

Acid phosphate 400 

Muriate of potash 600 " 

One ton of this mixture would furnish, approximately, 
105 pounds of nitrogen, 120 of phosphoric acid and 
300 of potash. The application of 1,000 pounds, 



NEISD FOB NITBOGEJ^r REDUCED 235 

therefore, would furnish the food in sufficient abun- 
dance and in good proportions to meet the demands 
of a fair crop. 

The advantage of using so large a proportion of 
nitrogen in the form of nitrate of soda in this ease 
is, that it is immediately available, inducing the im- 
mediate and rapid growth of plant, and preventing a 
too late growth by furnishing a minimum of organic 
nitrogen, which would become available late in the 
season. The cost of the fertilizer suggested in these 
cases is high, and the necessity of so expensive a 
dressing could be materially reduced by decreasing 
the need for nitrogen, particularly in organic forms, 
which may be accomplished by sowing crimson clo- 
ver with or after the previous crop of, say, corn or 
tomatoes. If weather conditions are favorable, crim- 
son clover may be sown in the tomato fields in 
August, after cultivation has ceased, or at the last 
cultivation, and a crop of clover grown which will 
provide nitrogen for the next year's crop. This 
method is now practiced with advantage by many 
growers. The late crop, like potatoes and sweet pota- 
toes, is usually grown in rotations in which it is the 
chief money crop; hence the unused residue from fer- 
tilizers applied in large amounts, as here indicated, 
contributes largely to the economical growth of sub- 
sequent crops. 

SUGAR BEETS 

The purpose in the growth of sugar beets is to 
obtain the largest total yield of sugar per acre; and 



236 FERTILIZERS 

inasmuch as the sugar content of the beet, as well as 
its right growth and development, is very largely 
influenced by the character of the fertilization, this 
matter becomes of very considerable importance, in 
view of the promising develoi)ment of the sugar beet 
industry in this country. Thus far, information con- 
cerning the use of fertilizers is derived largely from the 
results obtained in other countries, where it has been 
a prominent crop, and where great attention has been 
paid to this factor in its production. 

T/j-e Demands of lite Crop for Plant -food 

The sugar beet draws heavily upon the soil for the 
nitrogen and potash constituents. A minimum yield of 
10 tons of topped beets contains 44 pounds of nitrogen, 
20 of phosphoric acid and 96 of potash. On medium 
loamy soils, which by their character are well adapted 
for the growth of the sugar beet, heavy fertilization 
with potash, however, has not been found to be de- 
sirable; while on light soils, which are also well adapted 
for the crop, liberal manuring with potash becomes 
absolutely necessary. 

As in this crop, the object of the growth is to se- 
cure not primarily beets, but sugar, and since the sugar 
formation is not perfected until the absorption of the 
necessary food from the soil has been in large part 
completed, any fertilization which promotes a too rapid 
or too long continued growth has a tendency to reduce 
the percentage of sugar; and inasmuch as the matu- 
ration takes place largely in the months of early fall, 



FERTILIZATION OF SUGAR BEETS 237 

the growth must be forced early in the season. That 
is, it is essential that a large and rapid leaf growth be 
made early, in order that the food from the air may be 
acquired. It has been demonstrated that for this early 
and rapid growth of the beet, phosphoric acid is one 
of the most essential constituents, which explains the 
need for phosphoric acid in larger proportion than is 
indicated by the composition of the beet. The crop 
requires a considerably greater supply of phosphoric 
acid at this stage of its growth than other farm crops 
which are quite as exhaustive, and it is also evident 
that in order that the crop may obtain the phosphoric 
acid at this period, it must be soluble and immediately 
available; hence the larger portion of this element 
applied should be derived from superphosphates. In 
the matter of fertilization with nitrogen, the object of 
the growth must also be kept in view. An application 
which would encourage steady and continuous growth, 
rather than an early and rapid growth, while contrib- 
uting to a large yield, causes a reduction in the sugar 
content of the beet. Hence it is strongly urged by 
those who are in a position to give sound advice, that 
the early nitrogen fertilization should consist of the 
quickly available forms, nitrate or ammonia, and that 
the organic or slower -acting forms should not be 
applied in such excess as to encourage a late growth. 
Hence it is, that upon medium and light lands the use 
of commercial fertilizers has proved of greater service 
in the growing of this crop than the exclusive use of 
yard manure, and in such quantities as to supply the 
entire needs of the plant. In the use of fertilizer, not 



238 FERTILIZERS 

only the total supply of the constituents, but their 
form, may be regulated to the needs under different 
conditions, thus permitting a full feeding of the plant, 
and at a time most suitable to accomplish the object 
in view, — advantages which are not possessed by the 
natural manures. 

A fertilization which would meet the needs both in 
respect to quantity and kind of fertilizers, may be as 
follows : 

On good soils, the application or a fertilizer con- 
taining from 40 to 50 pounds of nitrogen, from 50 to 
60 of phosphoric acid and from 40 to 50 of potash, 
would be sufficient to meet the demands of the plant. 
The nitrogen supplied should be derived largely from 
nitrates or ammonia, or both, and the phosphoric acid 
from a superphosphate, while the potash may be de- 
rived from sulfate or muriate of potash. The former 
is preferable if applied during the spring preceding 
the planting of the beets. While it is frequently 
desirable, for convenience and economy of labor in 
applying, that the fertilizer should be mixed, in order 
to prevent any waste of soluble nitrogen, it should be 
applied in fractional dressings. For example, a mix- 
ture of 250 to 300 pounds of nitrate of soda (or, the 
nitrogen may be derived partly from nitrate and partly 
from ammonia), 400 to 500 pounds superphosphate, 
and 80 to 100 of muriate or high-grade sulfate of 
potash, should be applied in two or three dressings. 
A part only should be applied previous to sowing, for 
both the nitrate and the potash salts have a depress- 
ing effect upon germination. They are preferably ap- 



ADVANTAGES OF DEEP CULTIVATION 239 

plied, say, one -third of the mixture as soon as the 
plants have come up, another third immediately after 
or before the first cultivation, and the remainder 
immediately after or before the second cultivation. 
The application of the fertilizers in these forms and 
at the times indicated insures the rapid and early 
growth and development of the plant ; and by reason 
of the solubility of the nitrates and ammonia salts, a 
late feeding of the plant with nitrogen is obviated. 

On light or medium soils, the amount of plant- 
food should be increased by at least one -third, though 
fractional applications should be made as previously 
recommended. On soils rich in vegetable matter, a 
part of the nitrogen may be omitted, though the phos- 
phoric acid should not be reduced. 

The Influence of Previous Deep Cultivation of Soil 

Another point to observe in the growing of beets 
for sugar, — and it also has an immediate bearing upon 
fertilization, — is the character of the previous cultiva- 
tion. If the soils have not been deeply and well culti- 
vated, so large a dressing as is here recommended 
would be likely to be deleterious, as with a shallow 
and poorly prepared soil plants would have less op- 
portunity to penetrate deeply, and thus too great a 
growth above the surface of the ground would be 
encouraged, with a consequent lowering of sugar con- 
tent as well as yield. 

The best practice in our country will have to be 
developed by the experience of our own growers, 



240 FERTILIZERS 

though in the absence of such experience, the recom- 
mendations here made may be relied upon. In many 
of the sections of this country in which the soils and 
climate are well adapted for the sugar beet industry, 
the needs as yet are quite as much for improved 
methods of cultivation as for added fertility. They 
have not been exhausted of their essential elements 
of fertility. 

An epitome of the soil conditions for sugar beet 
culture will be found in the second edition of 
Roberts' "Fertility of the Land," p. 405. 



CHAPTER XII 

GREEN FORAGE CROPS 

A LARGE number of crops is included in this class. 
In dairy districts they are grown for summer feeding, 
mainly to supplement or to entirely substitute pas- 
turage, as well as to provide a succulent ration of 
roughage in winter. Any crop which grows quickly, 
is palatable, and makes a reasonably large yield, is 
adapted for the purpose. For convenience of study, 
these crops may be further classified into three 
groups : 

1. Cereals and grasses. 2. Clovers and other 
legumes. 3. Roots and tubers. 

In the case of those included in the first group, the 
purpose or object is to obtain as large a growth of 
leaf and stem as possible. Thus the character of the 
fertilization may differ from that recommended when 
the same crops are grown for the primary purpose of 
obtaining the largest yield of seed or grain. These 
crops, too, may in all cases be considered as only well 
adapted for the " intensive " system of practice — that 
is, when the management is such as to encourage the 
largest yield possible per unit of area under the ex- 
isting conditions of climate and season. The natural 
fertility of the soil thus becomes a less important 
factor ; indeed it cannot be relied upon altogether, as 

p (241) 



242 FERTILIZERS 

the largest yield of succulent food is dependent upon 
a rapid and continuous growth, and hence the supply 
of plant -food must be relatively much greater than is 
the case when the cereals are grown for their seed. 
That is, forage crops, because succulence is a factor 
influencing quality, must, as a rule, be grown quickly, 
and in order that large yields may be obtained in a 
short period of time a relatively greater abundance of 
plant -food must be at their disposal than when the 
growth is distributed through a longer period. Be- 
sides, larger amounts of all of the food constituents 
are required for the production of the same amount of 
dry matter per acre than when grown for the mature 
crop, because the dry matter of the mature crop is 
richer in the constituents derived from the air and 
poorer in those derived from the soil, than the dry 
matter of the immature crop. 

Maize {Corn) Forage 

A valuable forage crop of the first group is maize 
(Indian corn), because it grows quickly, is well adapted 
for a wide variety of soils and climates, is extremely 
palatable, and is capable of producing large yields. 
The fertilization which has been recommended for the 
field crop is less desirable than one which furnishes a 
greater proportion of nitrogen, because of the greater 
need of this element, and because it encourages a 
larger leaf and stalk growth; and the greater the pro- 
portion of these in a corn crop the richer will be the 
dry matter in the important compound protein, and 



FERTILIZERS FOR CORN FORAGE 243 

nitrogen is the basic element in this group of nu- 
trients. 

When the crop is grown on good land on clover 
sod, which has been liberally manured, the fertilizers 
applied should be particularly rich in the mineral 
elements, phosphoric acid and potash. An application 
of 500 pounds of a mixture containing — 

Nitrogen 2 % 

Available phosphoric acid 6 % 

Potash 8 % 

would provide an abundance of food, even should 
unfavorable conditions intervene, but when grown on 
light, unmanured soil without sod, a larger amount of 
nitrogen should be used in connection with the min- 
erals. An application of 25 pounds of nitrogen, 35 of 
phosphoric acid and 50 of potash is as small a fer- 
tilization as should be recommended on soils of this 
character, since a yield of 10 tons per acre, containing 
25 per cent of dry matter — which is only a fair crop 
— would remove 60 pounds of nitrogen, 25 of phosphoric 
acid and 70 of potash. Hence, very large increases in 
yield could not be expected from smaller dressings, 
unless conditions were absolutely favorable throughout 
the entire period of growth. The nitrogen, as in the 
case of field corn, may be derived from organic sources, 
as the season of growth is the same — the summer — which 
is the most favorable for encouraging a rapid change 
of the organic nitrogen into the soluble nitrates. The 
phosphoric acid should be in large part derived from 
superphosphates, though since the season of growth 



244 FERTILIZERS 

and the character of the crop and of its cultivation are 
conditions all of which favor a rapid change of in- 
soluble into available forms, a portion may be sup- 
plied by ground bone or tankage. The potash may be 
kainit or muriate, though if kainit is used, it should 
be broadcasted and well worked into the soil before 
planting. 

Silage Corn 

Corn grown for the silo, while distinctly a forage 
crop, is, in its management, very similar to the field 
crop, and is not planted so thickly as to prevent the 
formation of ears. The object in its growth is, how- 
ever, to obtain a large yield of dry matter, somewhat 
richer in nitrogenous substance and poorer in starch 
and woody fiber than field corn. Hence the fertilizers 
for the crop on medium soils should be richer in 
nitrogen than for the field corn, where the primary 
object is the grain, and where heavy fertilization with 
nitrogen would encourage a disproportionate stalk 
growth. An application of 30 pounds of nitrogen 
(equivalent to 250 pounds of dried blood or 450 of cot- 
ton-seed meal), 40 of phosphoric acid (equivalent to 
300 pounds of acid phosphate), and CO of potash 
(equivalent to 120 pounds of muriate of potash), 
would provide for a marked increase in yield. 

Wheat and Bye Forage 

In the growth of cereal grains, the object is to 
secure as large a jdeld of grain as is possible under 



WHEAT AND RYE FOB AGE 245 

the conditions of climate and season, and only such 
development of leaf and stem as will contribute to a 
maximum yield of grain. Hence a too liberal nitrog- 
enous fertilization which encourages this form of 
growth may result in too great a proportionate yield of 
straw. This objection becomes an advantage when the 
cereals are grown for forage. 

The cereal crops, wheat and rye, if seeded in the 
fall, should, therefore, receive a fertilizer which shall 
especially promote leaf and stem growth ; and to ac- 
complish this purpose in the best manner, a rapid early 
fall growth, and a consequent deep rooting system, as 
well as an early and rapid spring growth, should be 
encouraged. Fertilizers most suitable are rich in 
nitrogen and phosphoric acid, and should contain 
potash also, if the land has not been previously well 
supplied with this element. The larger proportion of 
the nitrogen, however, should be applied in available 
forms as a top-dressing in the spring, rather than at 
time of seeding, thus reducing the possible loss of this 
element during the winter and early spring through 
leaching, besides providing the plant with it when 
most needed, and producing a crop richer in nitrog- 
enous substance. 

The ranker growth and somewhat coarser product 
resulting from this method of fertilization, while not 
desirable for grain crops, is not a detriment when the 
product is cut in its green stage for feeding, and the 
larger growth is accompanied by greater succulence. 

Where these cereal grains are sown mainly as 
catch crops following a corn crop which has been 



246 FERTILIZERS 

liberally fertilized with the minerals phosphoric acid 
and potash, the application at time of seeding may be 
light, and may consist only of nitrogen and phosphoric 
acid, — for example, from 200 to 400 pounds per acre of 
a dissolved bone ; and the top-dressing in the spring 
need not exceed 100 pounds of nitrate of soda per acre 
for the wheat, and 75 pounds per acre for the rye. 
For lighter soils, or for those not previously well fer- 
tilized, much heavier applications not only are required, 
but all of the constituents should be included, and 
the top -dressings should be made in spring, as already 
pointed out. 

Spring Rye 

For spring rye, an application of a fertilizer fur- 
nishing 10 pounds of nitrogen, 20 of phosphoric acid 
and 10 of potash per acre would be a sufficiently 
liberal dressing for the crop on good soils, since the 
plant possesses good foraging powers, though it is not 
so desirable a forage crop for northern climates as the 
winter rye. The nitrogen, in any case, should be in 
quickly available forms. 

Oats 

Oats and millet are also suitable crops for forage 
purposes, and are largely grown ; the first, because it 
is adapted for cool, moist weather, and makes a rapid 
early growth, and the second, because adapted for late 
spring seeding and for summer conditions. 

The oat crop for forage purposes is even more 



A PECULIABtTT OF TEE OAT CROP 247 

generally benefited by manuring than when grown for 
the grain, and the constituents particularly useful are 
nitrogen and phosphoric acid, though on sandy soils, 
and on those of medium fertility and not previously 
fertilized with potash, this element should also be 
added. 

A good dressing, keeping in mind the value of the 
possible increased yield, may consist of 12 pounds of 
nitrogen, 20 of phosphoric acid and 10 of potash, — the 
nitrogen largely in the form of a nitrate and the phos- 
phoric acid in soluble and available forms. 

The oat crop is peculiar in that shortly after the 
germination of the seed, there usually occurs a period 
of a week or ten days during which the growth is ex- 
tremely slow, which experienced farmers call the "pout- 
ing" period. While the exact cause of this well-known 
habit is not understood, it is believed to be due 
in part to the absence of available plant -food of the 
right sort early in the season, since liberal applications 
of nitrates and superphosphates seem to shorten the 
period of "pouting," if not altogether preventing its 
occurrence. Its avoidance for grain crops, while im- 
portant, is not so important a matter as in the case 
of forage crops, since an extension of the period of 
growth simply delays ripening, while in the latter,, 
delays not only prevent maximum growth within a 
certain time, but seriously interfere with rotations. 

Winter oats, which are successfully grown in the 
southern sections of the country, should be fertilized 
at time of seeding practically in the same manner as 
wheat ; that is, dressings furnishing small amounts of 



248 FEBTTLIZEFS 

nitrogen and considerable phosphoric acid, to be fol- 
lowed in spring with a top-dressing of nitrate of 
soda, not to exceed 100 pounds per acre. 

Oats and Peas 

Where oats are grown with field peas for the pur- 
pose of supporting the vines, as well as to obtain a 
larger yield than from either alone, the fertilizer 
should also contribute toward the increase in the 
pea crop, and .hence a greater abundance of the 
minerals should be applied, though it is very desir- 
able in this case, too, to encourage the rapid growth 
of the oats by reasonably liberal supplies of available 
nitrogen. 

Barley and Peas 

The growth of this combination of plants is a 
desirable one when late fall forage is needed, and as 
a crop is well adapted for fall conditions. The ferti- 
lization should be liberal, in order to encourage a 
rapid and large appropriation of food, which may be 
elaborated after light frosts occur. An application 
of 200 pounds per acre of a mixture of 100 pounds 
of nitrate of soda, 175 of acid phosphate and 25 of 
muriate of potash, will furnish sufiBcient and good 
proportions of the plant -food constituents. 

Millet 

The various kinds of millet are eminently sur- 
face feeders, and are particularly benefited by liberal 



THE FERTILIZATION OF MILLET 249 

applications of all the fertility elements. In fact, 
maximum forage crops of this plant cannot be ob- 
tained except when there is present in the soil such 
an abundance of all of the fertility elements as to 
enable a continuous and rapid growth. Both the 
nitrogen and phosphoric acid should be largely in 
immediately available forms ; hence nitrates and super- 
phosphates are recommended. The potash may be in 
the form of muriate. A crop of ten tons per acre of 
millet forage, of any of the Japanese varieties, which 
are very suitable for this purpose, will remove 50 
pounds of nitrogen, 25 of phosphoric acid, and 110 
of potash, practically all of which food is absorbed 
from the immediate surface soil. Good crops fre- 
quently reach this assumed yield ; hence, unless the 
land is in a high state of fertility, or has been pre- 
viously fertilized, it is necessary, in order to obtain a 
fair crop, to furnish by direct application at least one- 
half of the nitrogen and potash, and as much phos- 
phoric acid, as are contained in the crop. These 
amounts and kinds of plant -food could be practically 
supplied by a dressing of 450 pounds of a mixture 
made up of 150 pounds of nitrate of soda, 200 of acid 
phosphate, and 100 of muriate of potash, and such 
dressings have given excellent satisfaction in the 
New Jersey experiments with forage crops. 

CLOVERS AND OTHER LEGUMES 

These are among the most valuable of our summer 
forage crops : first, because of the time of their 



250 FERTILIZERS ' 

growth, they furnish food before spring -sown crops 
are ready ; second, because of their power of ac- 
quiring food from sources inaccessible to the cereals, 
they are less exhaustive; and third, they are espe- 
cially rich in the compound protein, the most useful 
substance contained in feeds. Since these crops gen- 
erally grow well on soils of medium fertility, many are 
inclined to regard them as able to subsist and make a 
good crop without liberal fertilization. It should be 
remembered, however, that the power which these 
plants possess of acquiring nitrogen from the air 
depends largely upon the supply at their command of 
the mineral elements, phosphoric acid, potash and 
lime ; the presence of these is of primary importance, 
and good crops cannot be grown on land deficient in 
these elements. In any event, therefore, liberal sup- 
plies of the minerals should be provided, in order that 
maximum yields may be obtained. On soils of medium 
fertility which are fairly well supplied with vegetable 
matter, the need for nitrogen is not marked, even in 
the early growth of the plant. On lighter soils, how- 
ever, a nitrogenous fertilization is often serviceable, 
because supplying nitrogen before the plant has ac- 
quired the power of obtaining it from the air. This 
practice enables the plant to make an early start, and 
prevents the delay in growth which sometimes occurs, 
particularly on light soils, during the period imme- 
diately after germination, when the plant is unable to 
obtain its nitrogen from sources other than the soil. 
A green forage crop averaging 10 tons per acre re- 
quii-es, on the average, about. 30 pounds of phosphoric 



FERTILIZEBS FOB SUMMER LEGUMES 251 

acid and 100 of potash, and the nitrogen which neces- 
sarily accompanies these amounts of minerals will 
reach, on the average, 100 pounds. If this element is 
drawn from the air, because provided with an abun- 
dance of minerals, it is manifestly economy to supply 
the full amount of these required, rather than omit 
them, and thus to limit the plant's power of acquiring 
this expensive element, since the value of the 100 
pounds of nitrogen gained is greater than the cost of 
both the phosphoric acid and potash required. 

Cow Pea and Soy Bean 

The clovers, which range in their length of life 
from annuals to perennials, are, too, able to obtain 
their necessary supplies of minerals more readily from 
soil sources than the distinctly summer crops, as the 
cow pea and soy bean, because of the longer period of 
preparatory growth in the case of the former. That 
is, clover or vetch, while it does make a very rapid 
growth through a short period, does not obtain all 
of its food during that period. In its preparatory 
stage of growth — fall and early spring — a very con- 
siderable amount of food, the larger proportion, in 
many instances, is obtained, which in its later stages 
of growth, is simply distributed throughout the entire 
plant ; while the cow pea and soy bean, on the other 
hand, must obtain the entire amount of food needed 
for their growth and development during a short 
period, and these crops reach their best stage of 
development for forage in two and one -half to three 



?52 FKRTILIZERS 

months from time of planting. Hence, these crops, 
which possess apparently greater foraging powers, and 
make their development during the season when con- 
ditions are most favorable for rapid change of in- 
soluble to soluble food in the soil, require, when the 
conditions of the land are the same in each case, a 
relatively greater abundance of the mineral elements 
than do the clovers, which can acquire food through 
a longer period. 

An application of 300 pounds per acre of a mixture 
of 200 pounds of acid phosphate and 100 of muriate 
of potash, which supplies 25 pounds of phosphoric 
acid and 50 of potash, would, on medium soils, be 
regarded as a sufficient annual dressing for clover crops ; 
whereas, in the case of the purely summer crops, the 
application could be increased one -half with profit. 
In the case of the summer crop, the phosphoric acid 
should be in a soluble form, because it is not economy 
to depend upon the conditions of climate, soil and 
season to change insoluble forms rapidly enough to 
provide for the continuous feeding of the plant, while 
for the clovers, less available forms may be used with 
advantage. 

Alfalfa, or I/ticeme 

This valuable crop, which was not formerly regarded 
as well adapted for the eastern states, can be success- 
fully and profitably grown if the soil is sufficiently 
deep and open and naturally well drained, and pro- 
vided it is supplied with an abundance of mineral 



ALFALFA OB LUCERNE 253 

food, consisting of phosphoric acid, potash and lime. 
Its habits of growth are such as to enable the harvest- 
ing of three or four green forage crops, and at least 
two hay crops annually. In order to meet the large 
plant -food demands thus made, the fertilization pre- 
vious to seeding must be not only liberal, but frequent 
top -dressings should be made. The phosphoric acid 
for these dressings should preferably be drawn from 
superphosphates, in order that ready distribution may 
be accomplished, while a large portion of that con- 
tained in the preparatory dressing may consist of the 
less soluble forms, as ground bone, natural phosphatic 
guanos, and fine ground rock phosphates. 

Twenty tons of alfalfa green forage, which may be 
regarded as a good annual yield for this plant from the 
two to four cuttings that may be made, will contain 
250 pounds of nitrogen, 50 of phosphoric acid and 
275 of potash. Assuming that the demands for soil 
nitrogen are confined to a short period immediately 
subsequent to the germination of the seed, the total 
required plant -food is still considerable, and is es- 
pecially severe upon the potash compounds of the soil. 
Hence, the fertilizers supplied should be particularly 
rich in this element. For eastern conditions, where 
soils possess a medium rather than a high potential 
fertility, heavy dressings of the minerals should always 
be made. A good preparatory fertilizer may consist 
of 20 pounds of nitrogen, equivalent to 125 pounds 
of nitrate of soda ; 75 of phosphoric acid, equivalent 
to 600 of acid phosphate ; and 200 of actual potash, 
equivalent to 400 pounds of muriate of potash per 



254 FERTILIZERS 

acre ; and annual top -dressings should provide at 
least 30 pounds of phosphoric acid and 100 of actual 
potash for the same area. 

Inasmuch as careful preparation of soil is necessary- 
previous to seeding, and since this can preferably be 
accomplished by the growth of cultivable crops, the 
fertilizers may be also partly applied to these rather 
than all at once immediately preceding the seeding, 
thus limiting danger of injury to germination by an 
application of so large a proportion of salts. 

Need of Lime for Legumes 

Another point that should be remembered in the 
fertilization of the leguminous plants is their need for 
lime. This is true of the clovers particularly, not only 
for the purpose of providing the plants with a suf- 
ficient amount of this element, but in order that any 
possible acidity of soil may be corrected, since the bac- 
terial life in the soil, which is essential in order that 
the plant may acquire its nitrogen from the air, is 
discouraged rather than encouraged by 'the presence of 
acid. Hence, all soils that are used for the frequent 
growth of leguminous crops should receive a dressing 
of lime, preferably in the fall ; 25 bushels of stone 
lime per acre, once in four or five years, is a suf- 
ficient amount for medium soils. 

The necessity for fertilization, and the method 
employed in "intensive" practice, are illustrated by the 
following scheme of growing soiling crops, now prac- 
ticed at the Experiment Farm in New Jersey. If an 



SOILING-CROP ROTATION 255 

abundance of food is not supplied, the continuous 
feeding and consequent constant and rapid growth of 
the plants, which are primary necessities of the sys- 
tem in order to maintain the rotation and to obtain 
maximum yields, are prevented. With proper man- 
agement in other respects, the scheme of rotation and 
fertilization will result in a gradual increase in the 
fertility of the soil. 

Scheme of Soiling Crops 

No. of Crop Time of Amount of Time of 

Acre Rotation Seeding Fertilizer Applied Harvesting 

Crimson Clover. .Aug. 11,'97| ^^^ '^«- ^'''^ Phosphate y 
>- 50 lbs. Muriate of potash > 

{100 lbs. Acid phosphate ^ 
50 lbs. Grouud bone j-Aug. 20, '98 

50 lbs. Muriate of potash J 
{25 lbs. Nitrate of soda ^ 
100 lbs. Acid phosphate lOct. 25, '98 
50 lbs. Muriate of potash J 

CrimsonCloTer..Aug.24,'97|^<'^^;?"-^/^*!P^°?^^*« , Ulay 10,'98 
^- 50 lbs. Muriate of potash J 



50 lbs. Muriate of potash . 
• 100 lbs. Acid phosphate ^ 



(-1UU IDS. Acia pnospuaie ^ 

Corn Junel0,'98< 50 lbs. Ground bone >Aug. 

I 50 lbs. Muriate of potash J 



io,'y8 



25 lbs. Nitrate of soda 






Barley and Peas. .Aug. 25,'98<^ 100 lbs. Acid phosphate |-Oct. 25,'98 
I 50 lbs. Muriate of potash J 

{50 lbs. Nitrate of soda "l 
100 lbs. Acid phosphate .. , „„ ,__ 

^« ,^ ^ J ,_ H^ly 20, '98 

50 lbs. Ground bone 
50 lbs. Muriate of potash J 
f 75 lbs. Nitrate of soda ^ 

Millet Aug. 1, '98 i 150 lbs. Acid phosphate loct. 1, '98 

t 75 lbs. Muriate of potash J 



256 FERTILIZERS 

So. of Crop Time of Amount of Timf of 

Acre Rotation Seeding Fertilizer Applied E arresting 



50 lbs. Nitrate of soda 






r- !.« in -no 100 Ibs. Acld phosphste . , ,„ ,„„ 

Corn May 10,98-^ ju }• July 10, '98 

50 lbs. Ground bone [ 

I .50 lbs. Muriate of potash J 

{25 lbs. Nitrate of sods ■, 
100 lbs. Acid phosphate I Oct. 10, '98 
50 lbs. Muriate of potash J 

150 lbs. Acid phosphate ^ 
u < 50 lbs. Ground bone >. 

' 25 lbs. Muriate of potash-' 

25 lbs. Nitrate of soda "| 

,-, , , r, > -l.in -no I 100 IbS. Acid phosphate , on .no 

Oats and Peas. . .April 20, 98 „ „ ^ , , J-June20,98 

2.) lbs. Ground bone 



i 50 lbs. Muriate of potash 



or. A , ,no -00 lbs. Acid phosphate !<-,., . 

Soy Beans Aug. 1, 98 I „„ „ „ .^ / ^ ^ >Oct. 1, ' 

'100 lbs. Muriate of potash > 



' 100 lbs. Muriate of pota 
l.")0 lbs. Acid phosphate -» 



98 



Rye Sept. 29, '97-^ 50 lbs. Ground bone VMay 1, '98 

* 25 lbs. Muriate of potash J 

„ r la lbs. Nitrate of soda •> 

'•''' Millet May 1, '98 M50 lbs. Acid phosphate ijuly 1, '98 



75 lbs. Muriate of potash J 

1- „ D T 1 on .no r200 lbs. Acid phosphate 1 „ ^ on ,«» 

Cow Peas July 20, '98! ^„ ,^ ,. .^^ I , . ^ Sept. 20, '98 

•^ 100 lbs. Muriate of potash J ^ 



potash - 
25 lbs. Nitrate of soda 



Oats and Peas... April 10. '98 ^*^° ^^'- ^'^'^ Ph"^Phate K^^^ ^^,^^ 

25 lbs. Ground bone 
t ."iO lbs. Muriate of potash | 

Soy Beans July j, .ggi -'"<> lbs. Acid phosphate U t. i. '98 

UOO lbs. Muriataof potash J 



25 lbs. Nitrate of soda 
(10 lbs. Acid phosphate 
50 lbs. Muriate of potash >* 



r 2o IDS. iNiirate or soaa -> 
Barley aud Peas. .Sept. 1, '98 | 100 lbs. Acid phosphate l-Nov. 1, 98 



FERTILIZERS FOR ROOT CROPS 257 

No. of Crop Time of Amount of Time of 

Acre Rotation Seeding Fertilizer Applied Harvesting 

(25 lbs. Nitrate of soda 1 
100 lbs. Acid phosphate , , ,„„ 
„- „ ^ , , Mune 1, '98 

25 lbs. Ground bone 
50 lbs. Muriate of potash J 



/-. T> T 1- -no f 200 lbs. Acid phosphate "1 , ,., ,„„ 

Cow Peas June lo, 98-^ ,^„ ,^ t,, . ^ i , ^ S Aug. 15, '98 

^-100 lbs. Muriate of potash J 

{25 lbs. Nitrate of soda 'i 
100 lbs. Acid phosphate I Oct. 20, '98 
50 lbs. Muriate of potash J 

{25 lbs. Nitrate of soda -> 
150 lbs. Acid phosphate l-May 5, '98 
75 lbs. Muriate of potash J 

(-100 lbs. Acid phosphate ^ 

Corn June 1, '98-| 50 lbs. Ground bone >Aug. 1, '98 

>- 50 lbs. Muriate of potash J 



{25 lbs. Nitrate of soda -< 
100 lbs. Acid phosphate j-Oct. 15, '98 
50 lbs. Muriate of notash J 



This scheme, which provides for two or three 
crops each season, has proved entirely practicable 
and successful when liberal fertilization is practiced, 
as here indicated. 

ROOT CROPS 

These crops are, as a class, exhaustive of plant- 
food elements, much more so, in proportion to the dry 
matter contained in them, than the cereals or legumes. 
It will require, for example, 20 tons of topped fodder 
beets or turnips to furnish as much total food as is 
contained in 10 tons of corn forage or silage, as the 



258 FERTILIZERS 

former seldom contain more than 10 per cent of dry 
matter, whereas the latter frequently' contain more than 
20 per cent ; yet on the average, 20 tons of roots will 
contain 6G pounds of nitrogen, equivalent to 400 
pounds nitrate of soda, 35 of phosphoric acid, equiva- 
lent to 300 pounds of acid phosphate, and 150 of 
potash, equivalent to 300 of muriate of potash, which 
amounts are far in excess of those contained in a corn 
crop, particularly of the minerals, phosphoric acid and 
potash. The nitrogen demands for the two crops are 
practically identical. In the case of both kinds of 
crops, these fertility constituents are obtained entirely 
through the roots from soil sources. 

In respect to fertilization, however, the root crops 
may be divided into two groups, very similar in their 
demands for plant-food, the first to include mangel- 
wurzels, fodder beets, sugar beets and carrots, and the 
second turnips, swedes (ruta-bagas) and rape. 

Fertilizers for Fodder Beets, Sugar Beets and Carrots 

The first group requires that the fertilization with 
nitrogen and phosphoric acid shall be liberal, and that 
these constituents shall be applied in readily soluble 
forms, in order to meet the large and early demands of 
the plant for them. Potash is also a very essential 
constituent, particularly upon soils of a light, sandy 
character ; upon clay loams, the plant is better able to 
obtain this element. 

In order to obtain a large amount of actual food by 
the growth of these crops, a large tonnage must be 



FODDL'B BEETS, SUGAR BEETS, CARROTS 259 

secured, and a large yield cannot be obtained unless 
provision is made for a continuous and rapid growth, 
and this again cannot be accomplished without an 
abundant supply of nitrogen and phosphoric acid, 
which, as already stated, are the elements which, more 
than any others, seem to rule the crop. 

In the case of sugar beets, the suggestion for fer- 
tilization when grown for sugar (Chap. XI), may be 
followed in large part. That is, particular attention 
should be given to the supply of nitrogen and phos- 
phoric 'acid, though when grown for forage it is im- 
portant not only to secure sugar, which constitutes a 
large proportion of the dry matter, but that the gross 
yield shall be much greater than in the former case. 
Hence, a liberal use of yard manure need not be 
avoided, and heavier dressings of nitrogen, which 
stimulates early leaf growth, may be made. 

For both fodder beets and sugar beets, an applica- 
tion per acre of 40 pounds of nitrogen, 50 of phos- 
phoric acid and 100 of potash, or 1,000 pounds of a 
fertilizer, containing — 

Nitrogen 4 % 

Available phosphoric acid 5 ?& 

Potash 10 % 

should insure a very considerable increase in yield on 
soils of medium fertility, provided the elements are 
drawn from the best materials. On light soil the fer- 
tilization should be still heavier, and the proportion 
of nitrogen increased. In fact, on soils poor in fer- 
tility and possessing good physical qualities, the con- 



260 FERTILIZERS 

tributions of plant -food by them may be largely ig- 
nored, and the dressings made large enough to supply 
the entire amount of food required by the crop. On 
such soils the nitrogen should preferably be applied in 
fractional di-essings and in quickly available forms, 
because it is essential that this element should be 
quickly absorbed by the growing plant. The minerals 
may be all applied in one dressing, though preferably 
in two, in order that the constituents may be well 
distributed throughout the surface soil. To better 
accomplish this, cultivation should follow each 
application. 

Turnips, Swedes and Rape 

In the case of the second class of crops, it has 
been shown that they are able to extract their phos- 
phoric acid from combinations not readily accessible 
to other plants. In fact, they respond so promptly to 
applications of this element, that frequently too little 
attention is given to the supplies of the other elements; 
yet in order to obtain satisfactory yields, these must 
also be added. An analysis of the turnip, for example, 
shows it to be rich in potash; hence it must naturally 
be a voracious feeder upon compounds containing this 
element, and while it seems to obtain it more readily 
from soil sources than many other plants, these sup- 
plies should not be depended upon, even on good soils, 
to meet its entire needs in this respect. A liberal 
supply of nitrogen is also demanded, particularly dur- 
ing the early growth. An application of a fertilizer 



TURNIPS, SWEDES AND RAPE 261 

containing 20 pounds of nitrogen, derived in part 
from nitrate, 40 of phosphoric acid, derived in large 
part from phosphates, and 40 of potash, derived from 
muriates, would be a fair dressing on soils of good 
character. On the poorer soils, the application of the 
constituents of the same kind and forms should be 
very largely increased. 

In these crops, as in those already mentioned, it is 
essential — and success depends upon this as much as 
upon any other factor — that the growth should be con- 
tinuous ; and in order that there shall be no delay in 
this respect, there must be an abundance of available 
food always at their command. 

TUBER CROPS 

In many sections the potato and sweet potato are 
grown for roughage. For these crops no different 
fertilization is recommended than that already outlined 
(Chapter XI) for the crops when grown for market, 
though in the case of sweet potatoes, soils not adapted 
for the growth of marketable tubers may be used. 



CHAPTER XIII 

MARKET- GABDEN CROPS 

A KNOWLEDGE of the principles of plant nutrition 
is perhaps more serviceable in market -gardening than 
in any other line of farming. This branch of farming 
cannot be profitably conducted either without suitable 
soils or without an abundant supply of plant -food. 
Both of these conditions are essential for the growth 
of high -class products. 

THE YIELD AND QUALITY DEPENDENT UPON 
CONTINUOUS AND RAPID GROWTH 

In these days, it is not only the yield of a definite 
area that must be considered, but the edible quality of 
the products that are put upon the market. Quality 
depends upon, or is measured bj', both appearance and 
palatability ; and palatability is determined by the 
succulence and sweetness of the vegetable, or its free- 
dom from bitterness, stringiness, and other undesirable 
characteristics which frequently exist, and which can 
be largely eliminated, provided the grower is thoroughly 
familiar with his business, assuming, of course, that 
varieties are the same in each case. It has been dem- 
onstrated that market -garden crops of the best quality 
are those which are grown under conditions which 

(262) 



FERTILIZATION IMPEOVJl'S QUALITY 263 

permit of a continuous and rapid development. Any 
delay in the growth of a radish or of lettuce is largely 
responsible for the sharp taste and pungent flavor of 
the former, and the bitterness and toughened fiber of 
the latter. The same principles hold true of early 
table beets and turnips. The beets become stringy and 
wiry in character, and are less palatable if during the 
period of normal growth there has been any delay. In 
a time during which there has been no progress the 
fibrous portion of the vegetable is toughened, and 
exists in too great proportion. In the case of the 
early turnip, if any delay in growth occurs, the quality 
is injured, and the peculiar, pleasant flavor, a charac- 
teristic of the perfect vegetable, is changed ; it becomes 
vinpleasant. The unfavorable conditions of growth 
seem to cause more or less reversion to the character 
of the original plant from which the improved type 
has been derived, mainly through selection and im- 
proved methods of cultivation. 

All these conditions of growth are not absolutely 
under the control of the grower ; as, for example, a 
lack of sufficient moisture and sunshine, the latter of 
which is certainly beyond his power to control. But 
given good natural conditions in respect to soil, and a 
favorable season, the one thing that more than any 
other controls the yield and quality of market -garden 
products is plant -food of the right amount and kind. 
In other words, in crops of this sort, any limitation in 
this respect usually results in a disproportionate re- 
duction in profits. Only under exceptional circum- 
stances is it economical to depend upon natural soil 



264 FERTILIZERS 

conditions for profitable crops, however favorable such 
conditions may be, because in successful practice the 
cropping is in the highest degree "intensive," and even 
the best soils are liable to be deficient in some essen- 
tial feature. 

It might seem from the discussion thus far, that for 
these crops the recommendations as to methods of 
fertilization might be briefly though fully expressed 
as follows : 

Apply a reasonable excess of all of the essential 
fertilizer constituents to all of the crops. Neverthe- 
less, because of the peculiarities of growth of the 
different plants, as well as the different objects of their 
growth, distinctions should be made in reference to the 
kinds and amounts of plant -food applied, and these 
distinctions should be borne in mind, in order that the 
most profitable returns may be secured. Market -gar- 
den crops may, however, be grouped according to 
similarity, both in character and object of growth, 
and each group fertilized in a similar manner, which 
obviates the necessity of extra labor in the preparation 
of fertilizers. 

ASPARAGUS 

Asparagus is one of the very important vegetable 
crops, and perhaps no other renders so profitable a 
return for proper manuring and fertilizing. It differs 
from the majority of the others in two essential par- 
ticulars. First, it is a perennial, the length of life 
of a bed depending largely upon the treatment; and 



FERTILIZERS FOR ASPARAGUS 265 

second, only one crop can be obtained in a season — it 
occupies the land to the exclusion of other crops. 
Hence, special efforts should be made to obtain as 
large a crop as the- conditions of season and climate 
will permit. With, this plant the yield and market 
quality of the crops depend upon the number and size 
of the shoots. In respect to quality, the demands of 
the different markets vary. Some of them require that 
the shoots shall be bleached and so cut as to present 
only a green tip, the remainder being perfectly white, 
while others demand that the shoot shall be green. 
But in both cases, the size of the shoot determines 
salability, and the size is largely measured by the 
methods observed in feeding the plant when other 
conditions are favorable ; that is, if not injured by 
disease or insects. Small, spindling shoots usually 
indicate that the crop has not been well cared for, or 
that the plant has been imperfectly nourished. 

The root is enlarged and invigorated by the char- 
acter of the growth of the tops, or summer growth of 
the plant after cutting is finished, and it is obvious 
that the manuring should be such as to encourage not 
only a rapid growth of shoots early, but a large and 
vigorous growth of tops later, which assists the growth 
of the roots in which energy is stored up for the pro- 
duction of the crop in the following year. Hence, 
not only the character but the method of fertilization 
is important, and it differs from that recommended 
for those plants which grow from the seed in one 
season and which must depend upon what they are 
able to acquire dui-ing their short period of growth. 



266 FERTILIZERS 

The Use of Salt 

It was formerly believed that one of the most 
important ingredients of manures for the asparagus 
plant was common salt, and that in any fertilization 
this substance should occupy a prominent part. 
Experience has shown, however, that while salt may 
not be harmful, there is no real fertility value in it. 
The crop may be profitably grown without its appli- 
cation, though it does no harm, and there is no objec- 
tion to its use except on the ground that it adds no 
essential fertility element, and its indirect benefit may 
be obtained more cheaply by the use of other ma- 
terials, which contain salt as a normal ingredient, — 
for example, kainit, the crude potash salt, which is 
one-third salt, though its market price is based solely 
upon its potash content. 

Fertilizers that Have Proved Useful 

Fertilizers which have been found very useful for 
asparagus are those which contain food both in im- 
mediately available and in gradually available forms. 
During the early growing season, the available food 
may be appropriated rapidly enough to cause an in- 
crease in the yield of shoots of that year ; and inas- 
much as the plant continues to grow until winter, the 
food that becomes gradually available is appropriated 
later, and contributes to the strength and vigor of 
the roots upon which the next year's crops depend. 
Furthermore, because the crop is gathered fi'om the 



DSJii OF A BASIC FORMULA 267 

early shoots, which are continuously removed for 
from one to two months, the root is continuously 
drained of its stored -up material, and at the end of 
the cutting season it has been very much reduced in 
vitality ; wherefore it is particularly desirable that 
available food be applied at this time also, in order 
to encourage a rapid and vigorous growth of the 
top, which aids in the storing up of food in the 
root. A fertilizer containing — 

Nitrogen 4 ^ 

Phosphoric iK'id 8 % 

Potash 10 % 

the nitrogen to be drawn from both soluble and 
organic sources, and the phosphoric acid from both 
superphosphate and ground bone, or tankage, and the 
potash from muriate, may be applied previous to set- 
ting the crowns, at the rate of 1,000 to 1,500 pounds 
per acre, and thoroughly worked into the soil. 

A Basic Fertilizer for Market- garden Crops 

For market -garden crops, a fertilizer of the above 
composition may be regarded as a basic mixture, which 
may be applied to all of the crops, leaving the specific 
needs of the different plants to be met by top -dress- 
ings, or applications of the other constituents. The ferti- 
lizer ingredients, nitrogen and phosphoric acid, should 
preferxfbly consist of the different forms, rather than 
to be all of one form, though the cost of the element 
will naturally regulate this point to some extent. 



268 FERTILIZERS 

That is, a part of the nitrogen should be nitrate or 
ammonia, and a part organic ; a part of the phos- 
phoric acid should be soluble (from superphosphates), 
and a part insoluble (from ground bone, tankage or 
natural phosphates). The soluble portions of both 
nitrogen and phosphoric acid contribute to the im- 
mediate needs of the plant, and the less soluble to 
its continuous and steady growth, and to the poten- 
tial fertility of the soil. 

For asparagus, this basic fertilizer may be applied 
at this same rate, — 1,000 to 1,500 pounds per acre, — 
at the time of setting the crowns, or even in greater 
amounts from year to year, preferably early in the 
spring, in order that the plant may have the whole 
season for the appropriation of the food. 

The specific fertilizer, in addition, should contain 
immediately available forms of food, and should be 
applied preferably immediately after or during the 
latter period of the cutting, in order to feed at once, 
and thus stimulate and strengthen the plant in its 
condition of lowered vitality, due to the continuous 
and large removal of the shoots. This application 
should also be liberal, since, as already indicated, 
limitations at this time may result in a greatly de- 
creased yield and a poorer quality of product the 
next year, and hence a reduction in profit. The best 
growers apply, in addition to the fertilizer recom- 
mended, and after cutting, not less than 250 pounds 
of nitrate of soda, 300 of superphosphate, and muri- 
ate of potash, or kainit, equivalent to 100 pounds of 
actual potash. 



FERTILIZERS FOR PEAS AND BEANS 269 

These recommendations as to the amounts of fer- 
tilizers may seem rather large to those who have 
been accustomed to light applications, but they are 
the minimum rather than the maximum amounts, as 
many growers have learned that the extra amounts 
applied are preferable to the smaller amounts, con- 
tributing not only to the length of life of the plant, 
but also to the total yield and size of the shoots, as 
well as to their edible quality, which is measured by 
their succulence and flavor. 

These suggestions as to fertilizers are for condi- 
tions where large amounts of organic or natural ma- 
nures are not readily obtainable. When these are 
used, they may serve instead of the basic fertilizer, 
but cannot well substitute the special applications 
of artificial fertilizers made after cutting is finished. 

PEAS AND BEANS 

Peas and beans of the various kinds and varieties 
belong to the legume family, and possess the power 
of acquiring nitrogen from the air ; they are, therefore, 
ordinarily placed in a separate class in respect to their 
fertilization with nitrogen. When they are grown as 
market -garden crops, however, it is frequently the 
wiser economy to apply nitrogen, particularly if they 
are raised upon land which has not been previously 
planted with these crops, and thus may not possess 
the specific nitrogen-gathering bacteria : because it is 
imperative that the plants should not only have an 
abundance of all of the food constituents, but that 



270 FERTILIZERS 

their food should be such as to cause as long a crop- 
ping period as possible, and nitrogen will contribute 
to this end. Hence, in the fertilization of these crops, 
while the minerals are the primary constituents needed, 
nitrogen should also be applied, and it should prefer- 
ably be in the organic forms, which encourage a longer 
period of growth, rather than in the single, active- 
form nitrate, more generally recommended for the 
quick -growing market -garden crops, because its com- 
plete solubility and immediate availability encourage 
a rapid growth and short period of development. The 
basic fertilizer recommended, if applied at the rate 
of 500 to 600 pounds per acre, will usually furnish 
suflicient nitrogen, and may, if necessary, be supple- 
mented by the application of amounts of superphos- 
phate and potash salts M-hich will add from 20 to 30 
pounds of phosphoric acid, and 60 to 75 of potash. 

BEETS AND TURNIPS 

The early table beet and the early turnip are very 
important market-garden crops. Wherever grown, 
whether in the South for the northern market, or in the 
middle states for the near-by market, earliness is a 
primary consideration ; and the earliness of the crop is 
determined largely by the amount and availability of 
the nitrogen and phosphoric acid applied. These are 
the two elements which, more than any others, modify 
and dominate the growth of these plants, and con- 
tribute to their profitable production as early market- 
garden crops. In the case of early turnips particu- 



EARLY BEETS AND TURNIPS 271 

larly, a difference of two or three days in the begin- 
ning of the harvest will often determine the profit or 
loss upon the crop. The experience of many growers 
confirms the view that for no other crop is the necessity 
for right fertilization more important. Since the early 
growth of these crops takes place before active nitrifi- 
cation begins in the soil, dependence for this element 
must be placed upon the nitrogen applied, and it is 
desirable not only that the soils should be well supplied 
at the time of planting with all of the constituents, 
but that frequent top -dressings of the soluble nitrate 
shall be made. Top -dressings are recommended be- 
cause the application of a sufiicient amount of the 
nitrogen in this form at the time of seeding might 
result in its considerable loss, since at this season rains 
often occur which are frequently so heavy as to cause 
a leaching of the nitrates into the drains or into the 
lower layers, and thus prevent the continuous feeding 
of the plant, and a consequent delay in growth. 

An application, therefore, of from 1,000 to 1,500 
pounds of a high-grade fertilizer, one of the compo- 
sition of the basic fertilizer already suggested (p. 267), 
is frequentlj^ employed at the time of seeding, followed 
by a top-dressing of from 50 to 100 pounds of nitrate 
of soda per acre once every week or ten days, for at 
least three or four weeks after the plants have well 
started. It will meet the requirements for added fer- 
tility. Such a practice, under average seasonal condi- 
tions, insures a continuous and rapid growth, and ob- 
viates to some extent the dangers liable to follow from 
too much rain or from drought. The frequent applica- 



'272 FERTILIZERS 

tions prevent losses from leaching if heavy rains follow, 
and, except in case of excessive and prolonged drought, 
the nitrate remains in solution, and is ready to be 
immediately absorbed by the plant. The advantage of 
earliness which is gained by the use of apparently 
excessive amounts of nitrogen is two -fold : a higher 
price is received for the product, and the cost of labor 
per unit of income is less. Quite as large yields may 
be obtained by smaller dressings, but the net [in- 
come is reduced as the time necessary for the growth 
of a marketable beet or turnip is increased. See also 
Chapter XII, in reference to this subject. 

CABBAGE, CAULIFLOWER AND BRUSSELS SPROUTS 

These large-leaved plants are all voracious feeders, 
and are specifically benefited by large applications of 
nitrogen and of phosphoric acid. Heavy applications 
of the basic fertilizer (p. 267), which is excellent, 
should be supplemented upon good soils with additions 
of nitrogen and phosphoric acid, and upon light soils, 
potash may also be added. Notwithstanding the fact 
that these crops are particularly benefited by nitrogen, 
the character of the edible portion or head of the dif- 
ferent plants is very largely infiuenced by the nature of 
the growth. Too rapid an early growth, due to an ex- 
cess of nitrogen, frequently results in an abnormal de- 
velopment of leaf, which is not accompanied by a 
proper formation of the head ; hence a part of the 
nitrogen essential for the growth of the plant after the 
head has begun to form should be applied at this time 



FURTILIZEBS FOR MELONS 273 

in an immediately available form, and a part in forms 
which will gradually feed the plant. A good method of 
fertilization, in addition to the application of from 
1,000 to 1,500 pounds per acre of the basic fertilizer, 
therefore, may consist of a top-dressing of 100 pounds 
of nitrate of soda and 200 of superphosphate per 
acre, after the plants have begun to make growth after 
transplanting. After the heads begin to form, another 
top-dressing of 200 pounds of nitrate of soda may be 
applied, which will contribute toward a rapid and 
continuous growth of head, provided an abundance of 
the minerals is present, as already indicated. 

A number of crops belonging to this group of 
plants require, in addition to a sufficient supply of 
plant -food, peculiar climatic conditions for their best 
crop development. Cauliflower, particularly, not only 
seems to be so influenced, but great skill and expe- 
rience are required on the part of the grower. It 
must be remembered, that while proper fertilization is 
essential, it is only one of the primary conditions of 
successful culture. 

CUCUMBERS, WATERMELONS, MUSKMELONS, PUMPKINS 
AND SQUASHES 

All these belong to one botanical group of plants, 
and are usually adapted for similar climatic and soil 
conditions, though watermelons and muskmelons of 
good quality are successfully grown only upon light, 
warm, sandy soils. The pumpkins, cucumbers and 
squashes may be readily grown to perfection upon the 



274 FERTILIZERS 

colder and more compact clayey soils. All of these 
crops seem to require an abundance of vegetable matter 
in the soil, in order to make their best growth. Hence, 
upon soils deficient in this respect, manures should be 
applied which are rich in vegetable matter. Composts 
in the hill have proved of especial advantage, as they 
seem to encourage an immediate feeding, and prevent 
delay in early growth. In the best growth of these 
plants it is also necessary that the mineral elements 
shall be available, and that the nitrogen shall be of 
such a character as to encourage a continuous rather 
than a quick growth of vine. That is, unless the 
quick -acting nitrates are applied very frequently, they 
are less desirable than organic forms of nitrogen. 
Hence, with the usual broadcast application of the 
basic mixture at the time of planting, together with a 
compost in the hill, further applications of organic 
nitrogen should be made, its character to be such as to 
promise a relatively rapid change into nitrate. The 
basic mixture may be re -enforced by any one of the 
following materials: 200 to 300 pounds per acre of 
cotton -seed meal, 100 to 200 of dried blood, or 300 to 
400 pounds of fine -ground tankage. Any organic sub- 
stance whose greater part will decay in one season will 
generally give better results than the nitrate, unless 
the latter is applied in frequent small top -dressings, 
because organic forms of nitrogen provide for a con- 
tinuous growth of vine and fruit, while too great an 
abundance of immediately available nitrogen as nitrate 
is liable to cause too rapid and large growth of fruit 
of poor quality. This does not apply in the case of 



FERTILIZER FOR CELERY 275 

cucumbers for pickling, where a large setting of im- 
mature fruits is desired. In this case, nitrogen in the 
form of a nitrate, if properly applied, will contribute 
to a large setting and a rapid growth of the fruits. 

CELERY 

Celery is another plant that luxuriates in a soil 
rich in vegetable matter, though the peculiar advan- 
tage of this natural condition of soil may be largely 
met where it is possible to secure an abundance of 
water and plant -food in soluble forms. In the ab- 
sence of an abundance of water, even the best judg- 
ment in application of fertilizers will not result in 
satisfactory growth. A heavy application of the basic 
mixture (p. 267) — a ton per acre, used at time of set- 
ting the plants — may be followed with advantage by 
frequent and reasonably heavy top -dressings of nitrate 
oflsoda, 100 pounds per acre or more, and well worked 
into the soil. This abundance of soluble nitrogen will 
contribute toward that rapidity of growth which is 
accompanied by the peculiar crispness and sweetness 
that gives edible quality to this vegetable. In the 
absence of sufficient water and food, not only is the 
growth of the plant retarded, but the quality of that 
obtained is materially influenced, since the develop- 
ment of the bitter flavor and fibrous character that 
frequently cause a reduced consumption of this valu- 
able plant is apparently encouraged. 

What has already been said concerning this vege- 
table is true of a number of others : the main thing 



276 FERTILIZERS 

is to see to it that such an abundance of available 
food of the right kind is provided as to make 
possible p, rapid growth when other conditions are 
favorable. This is one of the primarj^ necessities, if 
a high yield of good quality product is obtained. 

SWEET CORN 

In the case of sweet corn, the early crop is usu- 
ally the most profitable. The recommendations that 
are made for the fertilization of the field crop do not 
apply to this, because the object is not the matured 
crop, which makes its greatest development in July 
and August, the most favorable season of growth, 
but the early green product, which is often harvested 
before the field crop has fairly begun to grow. This 
early and rapid growth, therefore, cannot be attained 
by methods of fertilization suitable for the field brop 
(Chapters X and XII). It can be accomplished only 
when an abundance of the mineral foods is present, 
and when the nitrogen is in part, at least, in forms 
which may be directly absorbed, as much growth must 
be made previous to the time that nitrification takes 
place in the soil. 

The large quantity of well -rotted manure which, 
until recently, was practically the only manure used 
for this crop, while extremely valuable, can be in part 
substituted by a liberal dressing of the minerals, 
phosphoric acid and potash, and further supplemented 
by nitrogen in readily available forms. The use of 
the basic formula (p. 267), reenforced by an applica- 



NITRATES FOB SPINACH AND LETTUCE 277 

tion of nitrogenous materials, partly in the form of 
nitrate, and partly in quickly available organic forms, 
as blood, cotton -seed meal, or tankage, may be prac- 
ticed with advantage. 

EGG-PLANT, SPINACH, LETTUCE AND RHUBARB 

The egg-plant belongs to the same botanical family 
as the potato, and while specifically benefited by the 
fertilizers recommended for that crop, is improved 
by the further addition of nitrogen, which stimulates 
an early leaf growth. Good organic forms are quite 
as useful as the nitrates or ammonia, unless the latter 
are used frequently as top -dressings. 

Spinach and lettuce, grown for their tops or the 
edible portion of the leaf, are encouraged in their 
development by an abundance of available nitrogen, 
as this element is the one which contributes more 
than any other to formation of leaf. Abundant growth 
of the right sort is only accomplished when it is pres- 
ent in such quantities and in such forms as to con- 
tinuously supply the plant with its needs. Reasonably 
heavy dressings of the basic formula (p. 267), 1,000 
pounds per acre, or over, at time of planting, should 
be followed by a top-dressing of 100 pounds per 
acre of nitrate after the plants are well started. The 
late fall and winter growth of the spinach is espe- 
cially benefited by the application of nitrates. 

Rhubarb is a crop somewhat similar to asparagus, 
in that it is a perennial, and that the best fertilization 
is one which not only provides food for the growth of 



278 fERTILtZERS 

the immediate crop, but which encourages the growth 
of top after the regular crop is harvested, and thus 
restores the vitality of the plant, — which has been 
weakened by the continuous removal of the stalk and 
leaf, — and enables it to store up energy for the sub- 
sequent crop. An annual application of 1,500 pounds 
of the basic formula (p. 267) early in the spring, 
preferably plowed in, may be followed with advantage 
by a top-dressing of 150 pounds per acre of nitrate 
of soda in about two weeks after harvesting has be- 
gun, and a similar dressing after harvesting has 
ceased. These dressings should be cultivated into the 
soil, unless immediately followed by rain, which will 
distribute the salt into the lower layers of soil. Plants 
of this sort, from which only one crop can be secured, 
should be stimulated to the largest possible production. 

ONIONS, ONION SETS AND SCALLIONS 

The growing of onions, either from seed or from 
sets, and the growing of sets according to "intensive" 
systems of practice, requires a soil of a suitable physical 
character, and also that it shall be well supplied with 
all of the essential constituents of fertility. The 
minerals should be supplied in abundance by super- 
phosphates and potash salts, while the nitrogen should 
be supplied in the most active forms, and in even 
larger amounts than for many other crops. The 
present systems of growing these crops require that 
the sets shall be planted and the seed sown more 
thicklv than was formerly believed to be desirable, 



FERTILIZERS PREFERABLE TO MANURE 279 

which permits of a larger yield per unit of area, 
though it requires better culture and a very much 
larger quantity of available plant -food than was the 
case under the former rather " extensive " systems of 
culture. Except in the case of very early onion crops, 
immediate rapid growth after setting is not so essential 
as in the case of many other market -garden crops, and 
in the growing of onion sets, when the soil is richly 
provided with food, great care in management is 
necessary in order to secure a development of bulb 
that shall not be too large, in which case the salable 
quality of sets will be reduced. Hence, to avoid this, 
the seed should be spread thickly, in rows about 
3 inches wide, and the cultivable portion between the 
rows about 8 inches wide. With so large a portion of 
the surface area occupied with the crop, the danger of 
too large development from heavy fertilization is greatly 
reduced. 

In growing scallions, the soil should not only be 
richly provided with minerals and organic forms of 
nitrogen, as in the case of the other, but should be 
supplied early with soluble nitrate, in order to meet 
the demands for this element before it is available from 
soil sources. In the growing of crops which require so 
much hand labor as onions, fertilizers are also pref- 
erable to yard manures, because they are free from 
weed seed. Further, fertilizers do not contribute 
toward the development of insects or diseases, as is 
sometimes the case with manures, particularly with the 
product derived from city stables. 

A good general fertilizer for onion sets for soils of 



280 FERTILIZERS 

fair fertility may consist of about 50 pounds per acre 
of nitrogen in organic forms, as dried blood, cotton- 
seed meal or tankage, 60 of phosphoric acid, which may 
be partly in organic forms, as bone or tankage, and 
100 of actual potash, derived from a muriate. The 
application of a formula containing — 

Nitrogen f> % 

Phosphoric acid 6% 

Potash \0% 

at the rate of 1,000 pounds per acre, and well worked 
into the soil previous to planting, would furnish these 
amounts, and this application, together with a top- 
dressing of from 75 to 100 pounds per acre of nitrate 
of soda, or 60 to 75 pounds of sulfate of ammonia, 
two or three times at intervals of about three weeks, 
the first after the crops have well started, would pro- 
vide not only an abundance of food of the right sort, 
but the nitrogen when needed, without danger of loss. 

If the soil has been well dressed with a general 
fertilizer, as above described, the scallions should 
receive a dressing of nitrate just as soon as growth 
begins in the spring, as rapid and early growth at this 
season will, other conditions being equal, depend upon 
the supply of available nitrogen, and nitrogen in 
available forms is not usually present in the soil in 
s^nfficient quantities so early in the season. 

In all of the suggestions made as to the fertilization 
of market -garden crops, not only has the question of 
yield been kept in mind, but also the quality of the 



FERTILIZERS VS. MANURES 281 

product, "which is a measure of salability. The ques- 
tion is often raised as to whether the forcing of these 
crops by means of active fertilizers may not result in 
too coarse and one-sided a growth. Such growth does 
frequently follow a heavy fertilization with nitrogen, 
if accompanied by too light a fertilization with min- 
erals. The tendency of the plant is to make a normal 
development when a sufficiency of all of the fertility 
elements are present, but in these crops the object is 
really a one-sided growth in many cases, since that 
growth is usually better adapted for the purpose than 
that obtained under what may be regarded as normal 
conditions. It must be remembered, too, in the grow- 
ing of certain vegetables, such as radishes, celery, etc., 
or those in which the roots are the edible portion, that 
commercial fertilizers do not contribute any undesirable 
flavors. In fact, they are often largely responsible 
for those peculiar characteristics which give quality; 
whereas, when these vegetables are grown by the ex- 
clusive and necessarily excessive applications,— if large 
yields are to be secured, — of natural manures, unde- 
sirable qualities are frequently contributed by them. 



CHAPTER XIV 

OBCHARD FRUITS AND BERRIES 

It is not until within recent years that the question 
of manuring or fertilizing fruit trees and berries has 
come to be of particular interest. This is due primarily 
to the fact that demands for fruit and berries have 
been relatively limited as compared with the staple 
crops. Hence, fruit-growing as a business, or on a 
commercial scale, is comparatively new, though the 
opinion is quite prevalent among fruit-growers that 
trees, particularly, are indigenous to most soils, and 
grow freely like weeds, and that, therefore, orchard 
crops are not as exhaustive of the fertility elements 
as others. They cite, as an argument on this point, 
the fact that lands from which timber has been 
recently removed are much more productive than 
those upon which many regular farm crops have 
been grown. Scientific investigation and practical 
experience, however, teach that forest growth and 
fruit growth are quite different in respect to the 
needs of fertilizing elements, and that progressive 
fruit -culture demands that quite as much attention 
shall be given to the matter of providing proper 
plant -food as is now known to be desirable for 
the other and more common crops of the farm 
grown for profit. 

(aga) 



TB£ GROWTH OF FRUIT CROPS 283 

FRUIT CROPS DIFFER FROM GENERAL FARM CROPS, 

It is obvious that suggestions as to the character 
of the fertilization of the cereal crops, grasses and 
vegetables, must be somewhat different from these 
fruits, because the former differ from the latter not 
only in their habits of growth, but in the character 
and composition of the crop produced, and in their 
relation to soil exhaustion. General farm crops, with 
few exceptions, require but one year for the entire 
processes of vegetation and maturation. Fruit crops, 
as a rule, require a preparatory period of growth of 
tree or bush before any crop is produced, which is 
longer or shorter according to the kind of fruit. 
Furthermore, after the fruit -bearing period begins, 
the vegetative processes do not cease, but are coinci- 
dent with the growth and ripening of the fruit. The 
crop product, or the fruit, also differs materially in 
its character from the general farm crop, or from 
vegetables, which reach their harvesting stage and 
die in one season, because for many kinds a whole 
season is required for growth and development. 

That is, in fruit-growing it is necessary that there 
shall be a constant transfer of the nutritive juices 
from the tree to the fruit throughout the entire grow- 
ing season, while the growth for each succeeding year 
of both tree and fruit is dependent upon the nutrition 
stored up in buds and branches, as well as upon that 
which may be derived directly from the soil. 

"In the next place, the relation of fruit-growing 
to soil exhaustion is very different from that in gen- 



284 FERTILIZERS 

eral-crop farming, because iu orchards there is an 
annual demand for specific kinds and definite pro- 
portions of soil constituents. It is really a continu- 
ous cropping of the same kind, and there is no oppor- 
tunity, as in the case of ordinary farm crops, to cor- 
rect the tendency to exhaustion by a frequent change 
of crops, or the frequent growth of those which re- 
quire different kinds and amounts of plant -food con- 
stituents." * 

THE SPECIFIC FUNCTIONS OF THE ESSENTIAL 
FERTILIZING CONSTITUENTS 

It must be admitted, however, that the general 
principles of manuring, as applied to farm crops, also 
apply to fruit and berry crops ; that is, the essential 
manurial constituents must be the same. 

"A fruit tree will not make normal growth in a soil 
destitute of nitrogen. That nitrogen encourages leaf 
growth is a recognized fact, and since trees grow by 
means of both leaf and root, its presence is required in 
the soil in order to promote the growth and extend the 
life of the tree. It is very evident, too, that potash is 
an essential constituent in the growth of fruits, not 
only because it constitutes a large proportion of the 
ash of the wood of the apple, pear, cherry and plum, 
and more than 50 per cent of the ash of fruit, but 
because it forms the base of the well-known fruit acids. 
Phosphoric acid is also very essential in order to 



♦Voorhees, "Manuring Orchards." Lecture before MassachusetteB Hortl- 
eultoral Society, 1896. 



SOILS ADAPTED FOB FRUIT CROPS 285 

nourish a tree properly, as well as to insure proper 
ripening, though it is apparent from such investigations 
as have been made that this constituent is relatively of 
less importance than for the cereals. 

"It is also a matter of common observation, that in 
the production of stone-fruits, particularly, lime is an 
important constituent. Its functions seem to be to 
strengthen the stems and woody portion of the tree, to 
shorten the period of growth, and to hasten the time 
of ripening. Fruit trees growing on soils rich in lime 
show a stocky, steady, vigorous growth, and the fruit 
ripens well, while those on soils which contain but 
little lime, particularly the clays, appear to have an 
extended period of growth, the result of which is that 
the wood does not mature and the fruit does not ripen 
properly." * 

THE CHARACTER OF SOIL AN IMPORTANT CONSIDERATION 

Soils which possess good mechanical condition, 
are rich in the essential constituents — nitrogen, phos- 
phoric acid and potash — contain a good propor- 
tion of lime, and are well di*ained and cultivated, are 
naturally well adapted for fruit trees, as well as for 
other crops, and the exhaustion of such soils will not 
become apparent for a long time. But soils of this 
character are the exception rather than the rule, and 
the growth of fruit on those which possess the opposite 
characteristics cannot be continued for any considerable 
period without an artificial supply of the fertility 

*'* Manarins Orchards." Massachusetts Horticultural Society, 1896. 



286 FBBTILIZEBS 

elements. Tn fact, it is doubtful whether it ever pays 
to attempt to grow fruits on soils of the latter char- 
acter without supplying them with an abundance of 
the essential fertilizer elements. 

In the matter of berries, which are crops especiallj'' 
well adapted to soils which possess a light, open 
character, but which are not naturally supplied with 
the essential plant -food constituents, proper manuring 
becomes of even more importance than for the tree 
fruits ; though, because of their shorter period of life, 
one or two good crops may be secured without heavy 
fertilization. 

On the whole, however, for all of these crops the 
great need at the present time is for a larger use of 
fertilizing materials, not only because a larger yield 
may be obtained thereby, but because the quality of 
tlie product is far superior to that grown under con- 
ditions which are not perfect in this respect. Quality, 
which is determined by size and appearance, is, other 
things being equal, largely dependent upon an abun- 
dant supply of plant -food. It is manifestly impos- 
sible to include all fruit and berry crops in one general 
group, though possessing points of resemblance, be- 
cause the different ones var}^ more or less in their 
character. The trees of certain of them are long-lived 
— 40 years or more, — while others are comparatively 
short-lived — 10 years or less. In certain of them the 
cropping period is short; the fruit ripens at once, while 
in others the ripening period extends over a consid- 
erable time. They also differ in reference to their 
demands for plant -food, certain of .them requiring an 



NM'CESSITT FOR CONTINUOUS FEEDING 287 

abundance of available food, while others can readily 
absorb the food necessary for their growth from rela^ 
tively insoluble compounds. In the discussion, similar 
recommendations may be made in many cases, though it 
is desirable that each class of fruits shall be considered 
separately, and also that distinctions should be made 
between what are regarded as good soils, as medium 
soils and as poor soils, in respect to their content of 
plant -food. 

THE GENERAL CHARACTER OF THE FERTILIZATION 

It must be borne in mind, also, that inasmuch as 
the fruit crop is not derived from annual plants, but 
from perennials, the character of the feeding may be 
very different from that in which the entire plant 
serves as a crop, as is the case with the cereals and 
most vegetables. Hence, the fertilizers applied need 
not all be of such a character as to be immediatel}^ 
available. That is, the fertilizing materials may be 
such as to provide for a gradual and continuous feed- 
ing. Those forms which decay relatively slowly are, 
perhaps, quite as good, if not better, for many kinds 
of fruits than those which by virtue of their solubility 
and immediate availability are more stimulative in 
their character. Those fertilizers which do not con- 
tribute to the immediate feeding of the tree or plant, 
but rather add to the reserves of potential plant -food 
in the soil, should, however, in many cases be sup- 
plemented by those which act more quickly, in order 
to supply an abundance of available food at special 



288 FERTILIZERS 

times and seasons. In general, therefore, a basic 
formula, the chief claim of which is that it furnishes 
large percentages rather than specific proportions or 
forms of plant -food, may be more reasonably adopted 
for fruits and berries than for other crops, because 
it may be applied with advantage to all of the fruits, 
the amounts to be applied to be adjusted to meet the 
requirements of the different kinds of crop and the 
different kinds of soil. Fertilizers which have been 
found to be very serviceable for fruit crops have 
been made according to the following formulas, the 
materials of which are familiar to all, and may be 
readily obtained from dealers : (1) One part, or 100 
pounds each, of ground bone, acid phosphate and mu- 
riate of potash; or (2), a mixture of one and one -half 
parts, or 150 pounds, of ground bone, and one part, 
or 100 pounds, of muriate of potash; the mixture of 
either to be applied in all cases. For fruit trees on 
soils of good natural character, further additions of 
more active forms of the various constituents may 
not be needed, while on light soils, or those of a me- 
dium character, or for berries, they should be added. 

The chief point to observe is that an excess of 
nitrogen must be avoided, and that if this element is 
applied in active forms it should be used at such 
times as to enable the plant to appropriate it early 
in the season, and thus become assimilated before 
the beginning of winter, the danger from too great 
an excess of nitrogenous fertilizers being that it 
causes a too rapid growth of both wood and fruit, 
which do not ripen well. 



METHOD OF APPLICATION IMPORTANT 289 
THE APPLICATION OF FERTILIZERS FOR FRUITS 

A point which should be carefully observed iu 
the fertilizing of orchards is the method of applica- 
tion. The fertilizers should, as far as possible, be dis- 
tributed throughout the lower layers of soil, where the 
feeding roots are located. If applied wholly on the 
surface of the soil, the tendency of the root is to go 
to that point, or where the food is, and trees which 
have the larger proportion of the feeding roots near 
the surface are more liable to suffer from drought 
than those which have them distributed at greater 
depths in the soil. Hence, in the application of fer- 
tilizers to orchards, particularly in the early life of 
the trees, they should, as far as possible, be well 
worked into the soil, which may be readily accom- 
plished by applying upon the surface before plowing. 
The after -fertilization, if it seems desirable to leave 
the orchard in sod, may be upon the surface, though 
in that case the soluble fertilizers are preferable, 
since they would rapidly descend, while the insoluble 
would do so more slowly, or only as rapidly as they 
became soluble. 

THE FERTILIZATION OF APPLES AND PEARS 

The necessity for the application of fertilizers in 
the growing of apples and pears is largely due to 
the fact that it is really a continuous cropping of the 
same kind, and, therefore, more exhaustive than a 
cropping which removes more plant-food in the same 



290 FERTILIZERS 

period of time. While upon good soils the trees may 
be able to acquire sufficient food to mature maximum 
crops for a considerable period, the life of the tree, 
as well as the character of the fruitage, will be very 
favorably influenced by the fertilization. 

An experiment* bearing upon this point is very 
instructive, as indicating the need of manures for 
fruit trees, not only in reference to the amount 
removed, but also in reference to the proportions of 
the essential constituents required. This study shows 
that the plant -food contained in 20 crops of apples, 
of 15 bushels per tree, and 35 trees per acre, and in 
the leaves for the same period, amounts, in round 
numbers, to 1,337 pounds of nitrogen, 310 of phos- 
phoric acid, and 1,895 of potash. These amounts of 
plant -food are compared with the amounts that would 
be removed by 20 years' continuous cropping with 
wheat, assuming an average yield of 15 bushels of 
wheat per acre, and 7 pounds of straw to 3 bushels 
of grain; viz., 660 pounds of nitrogen, 211 of phos- 
phoric acid, and 324 of potash. By this comparison 
it is shown that the 20 crops of apples remove more 
than twice as much nitrogen, half as much again of 
phosphoric acid, and nearly three times as much pot- 
ash as the 20 crops of wheat. 

These results are valuable in indicating the rate of 
soil exhaustion by apple -growing. It is to be remem- 
bered, however, that the larger root development of 
the tree would enable it to draw its nourishment from 



♦Cornell Exp. Sta., Bulletin No. 103, "Soil Depletion in Respect to the 
Care of Frnit Trees." 



THE NEED OF FERTILIZERS 291 

a larger area of soil than is the case with wheat, and 
thus probably permit of normal growth for a longer 
period. 

Too many are satisfied with short crops of medium 
fruit, with off-years and with short-lived trees, largely 
because they do not know that all of these conditions 
may be improved by a proper feeding of the tree, and 
that such feeding will usually result in a very largely 
increased profit. 

Statistics gathered in the state of New Jersey* show 
that over 90 per cent of the commercial apple -growers 
in the southern and central sections use fertilizers or 
manures for their orchards, whereas, in the northern 
section about 70 per cent use manures. In the northern 
section the orchards are usually located upon soils of a 
very high natural strength, and which are peculiarly 
well adapted for the growing of fruits, while in the 
central and southern sections, the soils in many sections 
are of medium, if not of very low fertility. Hence, 
while the larger proportion of the growers use fertili- 
zers or manures upon the poor soils, a very considerable 
number use manures for orchards located upon soils 
which are regarded as of the best; yet all claim that it 
is a paying practice. 

There is also a difference in the time- at which 
manuring or fertilizing should begin. When the soil 
is naturally good the fertilization need not begin with 
the setting of the tree, as the food obtainable is usually 
sufficient to provide for a good growth of leaf and 



•Bulletin No. 119, New .Jersey Experiment Station. 



292 FERTILIZERS 

wood, and in many eases maximum crops of fruit for a 
number of j^ears, though even here fertilization should 
preferably begin as soon as large erops are produced, 
whereas, on the lighter soils, fertilization should 
begin when the tree is set. 

Tlie Amounts to he Applied 

For these crops, either of the basic mixtures sug- 
gested (p. 288) will provide a sufficient proportion of 
nitrogen, except possibly upon the more sandy soil. 
On light soils, the necessity for liberal fertilization with 
nitrogen is frequently apparent, in which case it may 
be applied in organic forms, preferably from materials 
that do not decay too rapidly, as tankage, or wool waste, 
and other waste nitrogenous materials, because they maj" 
be obtained more cheaply, and because they furnish the 
nitrogen quite as rapidly as is needed by the tree. In 
many cases it is possible to obtain the necessary nitro- 
gen from the growing of leguminous crops, as crimson 
clover, though when these are used they should be 
plowed down early in the spring, in order that their 
growth may not interfere with the growth of the tree. 
If they are allowed to remain until mature, they ab- 
sorb not only the food that may be necessar}^ for the 
growth of tree and fruit, but the moisture also, and 
thus they frequently injure rather than improve the 
crop prospects. 

On soils of good natural character, the fertilization 
of apples and pears should begin as soon as the trees 
reach the bearing period, and an annual application of 



ABUNDANCE OF MINERALS NECESSARY 293 

400 pounds per acre of either formula 1 or 2 should 
be made, preferably in early spring, and plowed in. 
As they grow older and the yield of fruit is larger, the 
amounts should be increased. While no definite rules 
can be laid down as to the most profitable amounts to 
applj', the best growers find that it pays to use from 
1,000 to 1,500 pounds annually of mixtures which 
furnish practically the amounts and kinds of plant- 
food contained in the formulas suggested. The profit 
is found, not only in the larger yield, but in the 
quality of the fruit and in the increased tendency 
toward continuous crops, and in longer life of the 
tree. On soils of medium character the fertilization 
should begin earlier, and the amounts of the basic 
fertilizer should be larger. In many cases, too, nitro 
gen, in addition to that contained in the basic formula 
should be added, the kind and form depending, per 
haps, upon the relative cost more than upon any other 
one thing, the minimum amount to be 20 pounds per 
acre, or an equivalent of 125 pounds of nitrate of 
soda. 

On poor soils, the necessity for fertilization is nat- 
urally greater than for either of the others. In fact, 
on these liberal fertilization — 500 pounds per acre of 
basic formula No. 2 — should precede the setting of the 
trees, and be continued annually. On these soils, too, 
green manuring as a source of nitrogen can be prac- 
ticed with safety for a longer period than in the pre- 
ceding case. In the presence of an abundance of 
minerals, the need for nitrogen is indicated by the 
color of the foliage. If it lacks vigor and is yellow in 



294 FERTILIZERS 

the spring, rather than green, a dressing of from 100 
to 150 pounds of nitrate of soda will supply the needs 
to better advantage than any other form. 

PEACHES 

Peaches differ from apples and pears in respect to 
fertilization, because the period of development of 
the tree, preparatory to bearing, is shorter, and be- 
cause the cropping is usually much more exhaustive. 
Hence, the demands for added plant -food are propor- 
tionately greater in the early life of the tree, and are 
different, because of their more rapid growth. That 
is, forms of nitrogen that are more available are pre- 
ferred to the slowly available materials recommended 
for apples and pears. 

The Need of Fertilizers 

The results of an experiment conducted by the 
New Jersey Experiment Station* are interesting and 
valuable, as bearing upon this point. They show the 
value of fertilization, not only in increasing the yield 
of crops, but in extending the period of life of the 
trees, and in overcoming unfavorable crop conditions. 
The soil upon which the experiment was conducted 
possessed only medium fertility, good mechanical con- 
dition, and was fairly representative of soils naturally 
well adapted for peach -growing. The fertilized plots 
received annually — 



♦Annual Reports of New Jersey Experiment Station, 1864-94. 



THE NEW JEHSEY EXPERIMENTS 295 

Nitrate of soda 150 lbs. 

Bone-black superphosphate 350 " 

Muriate of potash 150 " 

per acre, whereas the manured plot received manure 
at the rate of 20 tons per acre. 

The following tabular statement shows the results 
obtained : 

I. Thk Yield without Manure 

Baskets 

per acre 

1884-1891, inclusive, 8 years, average per year 65.7 

1884-1895, " 10 " " " 60.3 

1887-1891, " (5 crop years), average per year . . .105.0 

1887-1893, " 7 <. << .< << _ gg 2 

II. The Yield with Complete Chemical Manure 

Baskets 
per acre 

1884-1891, inclusive, 8 years, average per year 164.2 

1884-1893, " 10 " " " 183.4 

1887-1891, " (5 crop years), average per year . . .262.8 

1887-1893, " 7 «< << << << _ 262.0 

III. The Yield with Barnyard Manure 

Baskets 
per acre- 

1884-1891, inclusive, 8 years, average per year 169.5 

1884-1893, " 10 " " " 194.7 

1887-1891, " (5 crop years), average per year . . .271.3 

1887-1893, " 7 <' *. <> «. _ 276.8 

IV. The Relative Yield in an Unfavorable Season 

Baskets 
per acre 

1889, unmanurod 10.9 

1889, fertilized 152.? 

1889, manured 162.5 



296 FERTITAZERS 

"The first point of importance and value observed 
is in reference to the number of crops that were 
secured. On the unmanured land, the crops secured 
after eight years were so small as to materially reduce 
the average for the whole period, while for the ma- 
nured land the average for the whole period was not 
only not reduced, but very materially increased ; that 
is, the crops secured on these after the trees on the 
unmanured land had practically ceased to bear were 
greater proportionately than those secured previous 
to that time. This was true both for the fertilized 
and manured land. 

"In the next place, it is shown that the yield was 
very materially increased by the use of manures, 
either in the form of artificial or natural supplies, 
and the differences in yield derived from these two 
forms are very slight, indicating that very much 
smaller amounts of actual plant -food in quick -acting 
forms were quite as useful as larger amounts of the 
less available forms in which the food exists in 
natural manure products. 

"For the ten years, the fertilized plot received 250 
pounds of nitrogen, 560 of phosphoric acid and 750 of 
potash, while the yard manure plot received — assum- 
ing the average composition of yard manure — 2,000 
pounds of nitrogen, 2,000 of phosphoric acid and 
1,600 of potash; yet with eighty times as much 
nitrogen, nearly four times as much phosphoric acid 
and more than twice as much potash, the yield was 
but 113 baskets greater, or an average of \\ baskets 
per acre. 



FERTILIZEMS FOB GOOD AND POOR SOILS 297 

"In the third place, it is interesting to observe — 
and it is a point of great importance — the effect of 
an abundance of food in overcoming unfavorable 
weather or seasonal conditions. The year 1889 was 
extremely unfavorable, and the crop throughout the 
state was small. In this experiment the unmanured 
plot yielded at the rate of 10.9 baskets per acre, 
while the manured and fertilized plots both showed a 
yield exceeding 150 baskets per acre. The manure 
strengthened and stimulated the trees, and enabled 
them to successfully resist such conditions as were 
fatal to the crop on the unmanured land. 

"This point is one that is seldom considered in 
calculating the advantages to be derived from proper 
manuring, though it is of extreme value, since the 
expenses of cultivation, trimming, and interest on 
investment are quite as great in one case as in 
the other."* 

Methods of Fertilization 

On soils of good natural character, the necessity 
for fertilizing peaches is seldom apparent until after 
the first or second year of growth. That is, good 
soils will provide sufficient food for a normal develop- 
ment of leaf and wood, and any additional fer- 
tilization would have the tendency to unduly increase 
the tree growth. On medium and poor soils, the 
setting of the trees should be preceded by a fer- 



*" Manuring Orchards." Massachusetts Hoiticultural Society. 1896. 



298 FERTILIZERS 

tilization with one or the other of the basic mix- 
tures (p. 288), on the better soils No. 2, and on the 
poorer No. 1, at the rate of 400 to 600 pounds per 
acre, which should be followed by the application of 
the more soluble fertilizers immediately the trees begin 
to bear. The need of nitrogen is often very marked, 
and is shown by a lack of vigor of the tree. The 
soluble nitrates have proved very valuable as a source 
of this element, since from these the nitrogen may 
be appropriated by the roots during the early season, 
and which, if a sufficient abundance of the minerals 
is present, enables a normal development of leaf and 
branch. If the quick -acting nitrogenous fertilizers 
are applied late, or if too large applications of the 
slower -acting nitrogenous materials are applied early, 
the tendency is to provide for a continuous feeding 
on nitrogen, and thus encourage an undue develop- 
ment of leaf and branch, which does not permit the 
ripening of the wood before the beginning of winter. 
Thus on these soils, in addition to an annual applica- 
tion of the basic formula, from 100 to 150 pounds of 
nitrate of soda, 200 pounds of acid phosphate and 
100 of muriate of potash should be applied early in 
the season and carefully worked into the soil. 

For peach crops, too, green manuring with legumi- 
nous crops should be carefully carried out, since 
if too much nitrogen is added by this means, an 
abnormal growth of wood is encouraged, and a late 
ripening of the fruit occurs ; and injury to the tree 
may follow if the manuring crop is not used at the 
proper time, as already indicated. 



CAREFUL USE OF NITBOOEN 299 

Many orchardists use much larger amounts of fer- 
tilizer than is here recommended, though if the sug- 
gestions concerning the method of use are carried out, 
the quantities named will be found sufficient to supply 
all the needs of maximum crops. 

PLUMS, CHERRIES AND APRICOTS 

The fertilization of these fruits, when grown on 
the different classes of soils, need not differ materially 
from that recommended for peaches under the same 
conditions, though cherries, particularly, require in 
addition to the essential constituents, nitrogen, phos- 
phoric acid and potash, a relatively greater supply 
of lime, and this substance should be applied in 
addition to the regular fertilization. Care should 
also be exercised in the application of nitrogen, in 
order to prevent a too great development of leaf and 
branch. Unless these trees show a decided need for 
nitrogen, a medium application of the second basic 
formula (p. 288) will furnish sufficient for their needs. 

CITROUS FRUITS 

These products — the oranges, lemons, and the like — 
belong to a distinct class of fruits, and the experience 
already gained in their fertilization is such as to make 
applicable the suggestions concerning peaches, plums 
and apricots. On the lighter sandy soils of Florida, 
which are naturally well adapted for oranges, growers 
have found potash to be a specially important element 



300 FERTTLIZERS 

in manures. The nitrogen and phosphoric acid should 
be accompanied by a larger proportion of potash than 
is recommended for the stone fruits. Great care should 
be exercised in the use of nitrogen, though in the case 
of these semi-tropical crops, the danger from immature 
growth, as in the case of fruits for the more northern 
climates, is not so marked. 



SMALL FRUITS IN GENERAL 

These crops do not differ from those already dis- 
cussed in reference to their needs for liberal fertiliza- 
tion, yet because of their different character of growth, 
the method of fertilization should be somewhat dif- 
ferent. They are, as a rule, crops which require a 
shorter preparatory season, and have a shorter period 
of bearing life. The strawberry, for example, does 
not advantageously bear more than two crops without 
re -setting, whereas the blackberry and raspberry may 
range in life from four to eight years, and the goose- 
berry and currant are relatively long-lived, provided 
they are supplied with an abundance of food. In 
respect to their general character, they correspond more 
nearly with the vegetable crops than with the cereal 
grains, in that they possess a relatively higher market 
value and a lower fertility value than these, and the 
period of growth and development of the fruit is much 
shorter. Therefore, natural sources of plant -food may 
be largely ignored in their growth, and the more quickly 
available — particularly nitrogenous and phosphatic — 
materials supplied. 



AVAILABLE PLANT-FOOD RECOMMENDED 301 
STRAWBERRIES 

In the case of the strawberry, the preparatory 
period of growth of the plant before bearing is but one 
year, and the crop that may be obtained is largely 
dependent upon the strength and vigor of plant which 
has been acquired during this period. Hence, it is 
desirable that the soil in which the plants are set should 
be abuudantl}^ provided with the mineral elements, 
particularly with soluble and available phosphoric acid; 
hence an application of from 500 to 800 pounds per acre 
of basic formula No. 1 (p. 288) is recommended. The 
nitrogen should also be in quickly available forms, and 
should be supplied in sufficient quantities at time of 
setting the plant to enable it to mature, and thus to 
withstand the rigors of winter. Hence, an additional 
application of 100 pounds of dried blood, or its equiva- 
lent in nitrate of soda or ammonia, is advisable, par- 
ticularly on soils not previously well enriched with 
organic nitrogenous matter. In the spring of the sea- 
son during which the first crop is harvested, an appli- 
cation of a quick -acting fertilizer rich in nitrogen is 
desirable, since it not only provides for an early and 
strong growth of plant, but a better setting of fruit, if 
other conditions are favorable ; and frequently, with a 
full setting, top -dressings with nitrate of soda are 
useful, in order to insure the full development of the 
crop. Many growers, therefore, who have supplied the 
soil liberally with minerals and nitrogen, both at time 
of setting the plants and in the following spring, make 
top -dressings of nitrate of soda (about 100 pounds per 



302 FERTILIZERS 

acre), preferably after the plant has blossomed, in 
order to insure a sufficiency of this element. This 
should be applied at this time rather than later in the 
season, since later applications have a tendency to 
cause a soft growth of fruit, and thus injure shipping 
qualities, 

RASPBERRIES AND BLACKBERRIES 

Raspberries and blackberries also require a soil 
well enriched with the mineral elements, which insure 
an abundant and strong growth of canes. The need 
for nitrogen, while apparent, is less marked than in 
the case of the strawberries, and the slower -acting 
forms serve a good purpose, provided they are not 
applied in too great quantities, so as to encourage a late 
growth of plant, which does not fully mature. The 
main object is to obtain strong, well -ripened canes, 
and this can be accomplished with the slowly avail- 
able nitrogenous substances, provided an abundance 
of the minerals is present. An annual application 
in spring of 500 pounds per acre of basic formula 
No. 2 (p. 288) will furnish sufficient food on soils of 
good character, though on lighter soils additional 
nitrogen should be supplied, preferably in forms not 
too active. The practice of applying quick -acting 
nitrogen early in the spring, after plants have blos- 
somed, has been followed with great success, particu- 
larly upon the lighter soils, as it encourages a more 
complete development of fruit, though it should be 
used with caution, since the fruit canes of both the 



FERTILIZE FOB FBUIT, NOT WOOD 303 

present year and those which provide the plant for 
the next year naturally grow in the same bed, and 
the young canes may not mature properly if too 
heavy applications of nitrogen are made. 

CURRANTS AND GOOSEBERRIES 

These are crops which, under average conditions, 
are seldom heavily fertilized, though fertilizing is 
usually followed with great profit. They are less 
likely to need nitrogen than the other crops men- 
tioned, and a too heavy fertilization with this element 
has a tendency to encourage the development of mil- 
dew, the disease so common to these crops. In com- 
mon with the other crops mentioned, they should be 
abundantly supplied with the minerals, phosphoric 
acid and potash, and the basic formula already rec- 
ommended (p. 288) may be used in all cases with 
profit at the rate of 500 to 1,000 pounds per acre. 
The additional nitrogen needed may be provided by 
the slow -acting materials. Many growers find such 
waste products as wool and hair of great advantage 
in the growing of these crops. 

GRAPES 

Grapes are more exhaustive as a crop than most of 
the fruit crops, largely because of the larger total crop 
harvested, and the special need is for phosphoric acid 
and potash. These elements may be supplied by the 
basic formula (p. 288), and very liberal dressings are 



304 FEBTILTZEES 

recommended, — from 1,000 to 2,000 pounds per acre 
annually, — after the bearing period begins. On 
light soils, an annual spring dressing of nitrate of 
soda, at the rate of 200 pounds per acre, is also 
desirable, in order to encourage rapid and large 
early growth of leaf and vine, though this dressing 
may be omitted if the growth of clover as a green 
manure is practicable. The latter, however, as when 
used in connection with the other fruits mentioned, 
should not be allowed to mature, but rather be 
plowed down early in the season. 

The main point in the fertilization of all fruits is 
to provide an abundance of the mineral elements, and 
to give particular attention to fertilization with nitrog- 
enous materials. It must be remembered that it is 
the fruit, not the wood, that constitutes the crop, 
and that all the energies should be directed toAvard 
the development of such a tree or vine as will best 
contribute toward this end. 



CHAPTER XV 

FERTILIZERS FOR VARIOUS SPECIAL CROPS 

In addition to the generally familiar crops already 
described, there are certain special ones, not distinct 
from the others because they are of less importance, 
but rather because they are only grown in certain 
localities. 

COTTON 

Among these special crops, cotton takes first rank, 
because it is one of the leading crops of the country, 
occupying wide areas, and exercising fully as great 
an influence upon our agricultural prosperity as any 
other of our American staples. 

The climate suitable for the growing of cotton is 
confined to about one -quarter of the area of the coun- 
try, and in this area it occupies a more important 
position than any other crop grown there. 

In the earlier history of its cultivation, the methods 
employed were not such as to encourage the largest 
yield. In the first place, it was grown on the poorer 
soils rather than the more fertile, and after it had been 
grown consecutively upon the same lands for a number 
of years, and thus rapidly exhausting them, the 
planter, instead of attempting to improve the lands, 
T (305) 



306 FERTILIZERS 

either by better methods of culture or by the use of 
manures, extended the areas under cultivation. After 
the civil war, when it became still more necessary to 
change methods, fertilizers vrere looked to as the main 
reliance, rather than the improvement of the character 
of the soil, either by judicious rotation or by manur- 
ing. The results secured from the use of fertilizers at 
this time were so generally satisfactory that their large 
and indiscriminate use was encouraged, and this, with- 
out proper attempts at the improvement of the soil in 
other respects, hastened the time when such use did not 
give profitable returns. The very great importance of 
the crop to the agriculture of the leading cotton states, 
and the necessity of better methods of culture, were so 
fully appreciated that a scientific study of the crop was 
then entered upon, and the states largely interested 
planned, through the aid of their colleges and ex- 
periment stations, a wide series of experiments, which 
were directed toward the solution of the problems 
connected with the feeding of the plant. The results of 
these experiments have been fruitful of such valuable 
information as to warrant practical and specific sug- 
gestions which have a wide application, and which, if 
followed, will result in the improvement of the soil and 
in the economical increase in crop. 

As already stated, the cotton crop is not an ex- 
haustive one in one sense, though the methods of 
practice used in its growth have been wasteful, and 
thus have given rise to that belief. That is, a large 
crop of cotton does not remove from the soil a very 
considerable amount of the fertilizer constituents. 



IMPORTANCE OF PHOSPHOBIO ACID 307 

The following amounts are contained in a crop yield- 
ing 300 pounds of lint per acre :* 

Nitrogen 46 lbs. 

Phosphoric acid 12 lbs. 

Potash 30 lbs. 

Fertilizers for Cotton 

In regard to its need for fertilizing, cotton may be 
classed with the cereals rather than with the crops al- 
ready discussed ; and like the cereals, its best growth 
is attained when properly introduced into a rotation 
with other crops, and the annual food supply arranged 
in such a manner as to contribute to the larger yield of 
the immediate crop, as well as to furnish an unused 
residue which will provide for an increase in the yield 
of the succeeding ones. Of the constituents, phos- 
phoric acid seems to exercise a greater influence upon 
the growth and development of the cottqp plant than 
any other element, notwithstanding the fact that 
smaller amounts are contained in it than of either 
nitrogen or potash. That is, it appears that the plant 
must have an abundance of available phosphoric acid 
at its command in order that the other constituents 
necessary for a full crop may be freely absorbed, though 
on the soils adapted for the crop, which naturally vary 
widely both in their general and special physical char- 
acteristics, but are poor in the fertility elements, both 
nitrogen and potash must be applied, in order that 
maximum crops may be obtained. 



♦Farmers' Bulletin No. 11, Department of Agriculture, 



308 FERTILIZERS 

On the whole, therefore, though the "intensive" 
system is not generally practiced, fertilizers furnishing 
all of the constituents are superior to those which fur- 
nish but one or two; yet when proper rotations are 
practiced and leguminous crops are grown for the pur- 
pose of improving the physical character of the soil, as 
well as increasing its content of nitrogen, the percent- 
age of this element introduced into the fertilizer may 
be very largely reduced. 

The conclusions that have been arrived at by the 
experiments conducted in the various states have been 
very fully set forth in various publications,* and the 
following statements drawn from these indicate what 
are believed to be the advantages derived from the right 
use of fertilizers, and the best methods to be observed: 

"The cotton plant responds promptly, liberally and 
profitably to judicious fertilization. The maturation 
of the crop may be hastened, and the period of 
growth from germination to fruiting may be so short- 
ened as to increase the climatic area in which it may 
be profitably grown. It should be assigned to a 
place in a rotation system. One of small grain, corn 
(with peas) and cotton, is well suited for the con- 
ditions prevailing in the cotton belt, and, as with 
other crops, the results derived from the use of 
fertilizers for this crop are much enhanced by the 
proper preparation of the soil. It pays to bring 



♦Farmers' Bulletins, Nos. 14 and 48, Dopartmcnt of Aericulture. Office of 
Experiment .Stations, Bulletin No. 33, Department of Agriculture. Various 
bulletins issued by the Georgia, South Carolina and Louisiana Experiment 
Stations. 



FORMULAS FOB COTTON 309 

up the cotton lands by mechanical treatment, 
and especially by introducing organic matter. The 
renovating crops, especially the cow pea, are very 
profitably employed as adjuncts to the fertilization 
of the crop itself. On the majority of soils, too, it is 
advisable, and more generally proves profitable, to use 
a complete fertilizer, rather than one containing one 
or two of the constituents; and of the forms of nitro- 
gen, organic (vegetable and animal) is best suited 
to the cotton, if one form alone be used, although 
nitrate of soda is probably nearlj^ if not quite, of 
equal value. The relative advantages of various pro- 
portions of the different forms have, however, not yet 
been fully determined ; hence the use of a mixture 
of the best is a safe plan, the proportions to be 
determined by their relative cost. In the case of 
phosphoric acid, superphosphate is to be preferred to 
to materials of an organic or mineral nature, which are 
not immediately available. Of the potash salts, no 
particular difference is observed in the use of the 
different forms. The form to be secured is to be 
based upon the price of the different forms." 

Formulas for Cotton Fertilizers 

While the most judicious proportions of soluble 
phosphoric acid, of potash and of nitrogen in a com- 
plete fertilizer cannot be said to have been determined 
with entire accuracy, the carefully conducted experi- 
ments of both the Georgia and South Carolina sta- 
tions indicate that for general use 1 part of nitrogen, 



310 FERTILIZERS 

1 of potash, and 2% or 3 of phosphoric acid in- 
dicate the best proportions. The amount of fer- 
tilizer that may be profitably used very naturally 
varies widely, though medium rather than very large 
dressings are recommended, not so much because the 
plant under good soil conditions could not appropriate 
and use to advantage large amounts, but because on 
the whole, soils used for cotton are peculiarly lacking 
in those qualities which enable the proper distribu- 
tion and appropriation of the larger quantity. For 
those soils, then, the amounts per acre indicated by 
the Georgia Experiment Station are, annually — 

Nitrogen 20 lbs. 

Available phosphoric acid 70 " 

Potash 20 " 

The South Carolina Experiment Station recom- 
mends an application per acre of — 

Nitrogen 20 lbs. 

Available phosphoric acid 50 " 

Potash 15 " 

or, as suggested by the Georgia Experiment Station, 
perhaps a fertilizer containing — 

Nitrogen 3 % 

Phosphoric acid (soluble) 9 % 

Potash 3 * 

applied at the rate of 700 pounds per acre, would be 
approximately the best amounts to use under ordinary 
circumstances. 



ADVANTAGES OF HOMJi MIXlUB£S 311 

Method of Applicaiion 

The fertilizer should be applied in the drill at the 
time of planting, and at the depth of not more than 
three inches, and well mixed with the soil. In 
most cases it is best to apply all of the fertilizer in 
one application rather than in fractional applications, 
though with lands in superior condition profitable 
applications may be made again at the second plow- 
ing. Owing to the nearness of the cotton belt to 
the supplies of superphosphate, and to the cheap sup- 
plies of cotton -seed meal, the only fertilizer neces- 
sary to import is potash. Hence it has become a 
practice in most sections for the planter to make his 
own formulas, using his own supplies of phosphoric 
acid and nitrogen; and home mixtures, made up of 
acid phosphate, cotton -seed meal and muriate of 
potash, or kainit, are largely used to supply the 
demands. The following formula is an example of a 
good mixture : 

Acid phosphate 1,200 lbs. 

Cotton-seed meal 600 " 

Kainit 200 " 

The formula containing — 

Nitrogen 3 fo 

Phosphoric acid 9 % 

Potash 3% 

is also recommended, since an application of 700 
pounds per acre will furnish the amounts and propor- 
tions of the elements indicated as the maximum by 



312 FERTILIZERS 

the Georgia station. This formula is also well suited 
for corn, if introduced into a rotation as previously 
suggested. 

TOBACCO 

Tobacco is another special crop grown only in cer- 
tain localities, favored either by reason of climate or 
character of soil, or both. It is, however, a very 
important crop in this country, and one which requires 
very careful attention in reference to the amounts and 
kinds of fertilizers applied, because the fertilization 
exercises an influence upon both the yield and quality 
of the crop. It is an exhaustive crop, drawing heavily 
upon both nitrogen and potash. A crop yielding 1,000 
pounds of leaf per acre will contain, in round numbers, 
67 pounds of nitrogen, 9 of phosphoric acid and 85 of 
potash : amounts equivalent in nitrogen to over 400 
pounds of nitrate of soda, of phosphoric acid equiva- 
lent to 75 pounds of acid phosphate, and of potash 
equivalent to 170 pounds of muriate of potash. It is 
a fact, too, that tobacco of the best quality, or that 
best suited for cigar wrappers, can be grown to ad- 
vantage only on light, sandy soils, — those not natur- 
ally well supplied with the fertilizing constituents. 
Thus, if large crops are to be secured, the soil must 
receive liberal supplies of food from artificial sources. 

The Influence of Fertilizers on the Qualify of 
the Crop 

A point of great importance in the fertilizing of 
tobacco, is the influence of the constituents applied 



FERTILIZERS INFLUENCE QUALITY 313 

on the marketable quality of the crop, as for certain 
purposes, especially for the manufacture of cigars and 
cigarettes, the tobacco must possess peculiar charac- 
teristics in order to bring the highest price in the 
market. In other words, in the growing of this crop, 
as is the case in many others, both the yield and 
quality must be taken into consideration, and frequently 
the latter point is of quite as much importance as the 
former, though a reasonable yield must be secured 
before the influence of quality is of practical signifi- 
cance. The quality of the leaf is believed to be 
influenced chiefly by the constituent potash, though 
many growers object to the use of various nitrogenous 
and phosphatic materials, believing that they, too, 
exercise a decidedly unfavorable influence upon the 
quality of the leaf. Careful experiments, however, do 
not justify many of the opinions of growers and dealers 
regarding the effect of the different materials upon the 
quality of wrapper tobacco. 

The main points, therefore, in the fertilizing of 
tobacco, are to see to it that a sufficient quantity of 
plant -food is applied in order to secure the largest 
possible yield consistent with quality, and second, to 
avoid the use of such constituents as are positively 
injurious. 

The Conclusions from Connecticut Experiments 

Experiments in the application of fertilizers to to- 
bacco have been carried out at the Connecticut Exper- 
iment Station with great care and skill for a number 



314 FERTILIZERS 

of consecutive years.* They lead to the conclusion 
that "there is no 'best' tobacco fertilizer, or 'best' 
formula for all seasons, even on the same soil. A 
formula or a form of plant -food which in one season 
gives the leaf a somewhat better quality than any 
other, may, perhaps the next year and on the same 
soil, prove inferior to others, for reasons which can 
only be surmised. 

"Nevertheless, by comparing the effects of these 
fertilizers for a term of years, it appears that certain 
ones are, on the whole and generally speaking, more 
likely to impart a perfectly satisfactory quality to the 
leaf than certain others. 

"It is doubtless true of tobacco, as of other crops, 
that the liberal but not greatly excessive supply of 
readily available plant -food yearly required to insure a 
paying crop may be given in a variety of forms with 
equally good results, on the average of one season with 
another, and that, indeed, occasional changes in the 
form of nitrogen and potash supplied may be a distinct 
advantage, avoiding always any considerable quantity 
of those things, as chlorin, and sulfuric or other free 
acids, which experience has shown may damage the 
leaf." 

These conclusions in regard to the kind and quantity 
of fertilizing constituents required for the growing of 
tobacco of good quality confirm those arrived at by 
experiments elsewhere, and the suggestions made are 
sufficiently definite to guide in the use of fertilizers 

•Connecticut Agr. Exper. Sta., Annual Report, 1897, Part IV., page 255. 



DESIRABLE FORMS 315 

for this crop. In brief, therefore, the tobacco crop 
must be provided with an abundance of all of the fer- 
tilizer elements derived from readily available forms, 
and free from those constituents known to exercise an 
unfavorable influence upon the quality of the product, 
in order that satisfactory yields of good quality may be 
secured. 

Form of the Constituents 

It has not been shown that one form of nitrogen 
is superior to another under all circumstances, or in 
other words, that one form of nitrogen, — as, for 
example, ammonia or nitrate, or any particular form 
of organic nitrogen, vegetable or animal, — is superior 
to all others, but rather that any or all of the good 
forms may be used in a mixture, provided a sufficient 
abundance is present to insure a maximum yield, 
though not so large an amount in excess of the 
minerals as to encourage a rank, coarse growth. The 
phosphoric acid should be in available forms, and if 
in these forms, must naturally be drawn largely from 
superphosphates. The potash should in all cases be 
drawn from sources free from chlorids. A fertilizer, 
therefore, which contains the nitrogen, either in good 
organic forms, as cotton -seed meal or blood, or a mix- 
ture of these organic forms with ammonia or nitrate 
in not too large amounts, which contains the phos- 
phoric acid in a soluble form, and potash derived 
from products free from chlorids, — as from high-grade 
sulfate, or from a carbonate, or from cotton -hull 



316 FEBTILIZERS 

ashes, if these are obtainable, — may be regarded as 
well adapted for the croj>. 

Amounts to Apply 

An annual dressing which will furnish 100 pounds 
of nitrogen, 75 of phosphoric acid and 150 of potash 
per acre may be regarded as a minimum for soils of 
medium quality. On lighter soils heavier applications 
should be made, and on soils previously well enriched 
with the fertilizer constituents, the dressing may be 
somewhat less. It must be remembered, however, that 
it is not economical, from the standpoint of either 
yield or quality, to be too sparing in the applica- 
tion of fertilizers, because the plant requires large 
amounts of both nitrogen and potash, and because it 
is essential that the plant should have a reasonable 
excess of these at its command, in order to overcome 
as far as possible any unfavorable seasonal conditions 
that may occur. 

In the Connecticut experiments already referred to, 
amounts greatly in excess of those suggested have 
been used with advantage. In Kentucky and Vir- 
ginia, on soils naturally richer, smaller amounts have 
given quite as good results. 'Jt is likely, however, 
that upon the very light soils of certain of the 
states in which tobacco of high quality is grown, 
notably Florida, considerably increased amounts may 
be used with profit. 

As sources of at least part of the nitrogen and 
potash in the southern states particularly, cotton- 



FERTILIZERS FOB SUGAR-CANE 317 

seed meal and cotton -hull ashes are recommended, 
because readily obtainable. These forms have been 
found to be good, and they may be obtained as 
cheaply as other forms as well as more conveniently. 

SUGAR-CANE 

Another special crop, confined largely to one state, 
Louisiana, is sugar-cane, and perhaps no other one 
crop has in this country received such careful study 
in reference to its needs for plant -food. The Sugar 
Experiment Station of that state has for twelve years 
conducted a series of systematic experiments designed 
to answer the questions as to what the needs are 
for nitrogen, phosphoric acid and potash ; and the 
results of this work thus far secured furnish sugges- 
tions in reference to fertilization, which will, if care- 
fully followed, undoubtedly result in the production 
of better crops than are grown under present systems. 
Fertilizers are clearly needed, and their right use is a 
profitable practice, though, as stated by Doctor Stubbs, 
"many ascribe the failure from their use to the worth- 
lessness of the fertilizer, when it should be ascribed 
to some defection of the soil, rendering it incapable 
of appropriating the applied fertilizer." 

The chief conclusions in reference to fertilizers 
for sugar-cane in Louisiana, so clearly set forth by 
Doctor Stubbs in this report,* are here summarized, 
as it is believed that the underlying principles are 



*"Sugar-Caue," Vol. I, Sugar Experiment Station, Audubon Park, New 
Orleans, La. 



318 FERTILIZERS 

applicable elsewhere, though naturally their use must 
be modified to suit individual cases. 

The Needs of the Plant as Indicated by the 
Louisiana Experiments 

"An examination of the cane plant shows that a 
crop of 30 tons will remove, in round numbers, 102 
pounds of nitrogen, 45 of phosphoric acid and 65 of 
potash. It is, therefore, a relatively exhaustive crop, 
and unless the physical conditions are perfect, even 
good soils should receive considerable di'essings of the 
constituents, if the fertility is to be maintained. 

"The results secured thus far in the experiments 
referred to demonstrate that the soil needs nitrogen 
and phosphoric acid particularly, in order to grow 
cane successfully, while thus far, no results of any 
character, either in the increased sugar content or 
tonnage per acre, have been visible from the use 
of any form of potash upon the alluvial lands of 
the lower Mississippi. Several forms of potash, 
notably the carbonate, and ashes of cotton-seed hulls, 
have rather decreased the yield of cane and injured 
the physical qualities of the soil by causing it 
to 'run together.' 

"In reference to the form and amount of nitro- 
gen, it has been shown that sulfate of ammonia 
gives slightl}'^ better results than any other form, 
though its higher cost gives no advantage over those 
costing less, while cotton -seed meal comes next, fol- 
lowed by dried blood and nitrate of soda. In refer- 



LOUISIANA EXPERIMENTS 319 

ence to the amount of nitrogen to be applied, it is 
shown that not less than twenty -four pounds nor more 
than forty -eight pounds per acre should be applied. 
Naturally, different soils and different kinds of 
cane would vary in their requirements for this 
element, and the amount needed would also be in- 
fluenced by the method of growing the crop : whether 
upon 'succession' land — that is, upon soils upon which 
a crop of stubble cane has just been taken off, and 
which has been in cane for a number of years with- 
out the intervention of a leguminous crop between to 
restore the nitrogen — or whether upon pea -vine land, 
upon which the plant cane is grown the first year, 
stubble cane the second, and corn and cow peas the 
third year. This system of rotation, which intro- 
duces a leguminous crop into it, not only improves 
the physical quality of the soil, but enables a con- 
siderable accumulation of nitrogen, frequently over 
one hundred pounds per acre. The pea -vine lands, 
put in plant cane on account of their excellent physi- 
cal condition, not only yield up readily the nitrogen 
stored up by the pea, but can also assimilate larger 
quantities of plant -food applied as fertilizer. Hence, 
such cane usually makes large crops. Since nitrogen 
is the chief ingredient taken from the soil by a crop 
of cane, it follows that with each successive crop of 
cane grown on the land without the interjection 
of the leguminous nitrogen there arises an increased 
demand for nitrogen. Hence, stubble cane requires 
larger quantities than plant cane, and the older the 
stubble, the larger its requirements for this element." 



320 FERTILIZERS 

In reference to phosphoric acid, the results so far 
indicate positively the value of this element in fer- 
tilizers for sugar-cane on these soils, but the demand 
for this ingredient is small in comparison to that for 
nitrogen, 36 pounds per acre being ample for the crop. 
The results further show that the soluble forms of 
phosphoric acid are preferred. Inasmuch as the legu- 
minous crop does not add to the store of phosphoric 
acid in the soil, it is equally needed by both plant and 
stubble cane. 

While potash has not been shown to be needed on 
the land upon which the experiments were conducted, 
because of the abundance of potash contained in the 
soil, after continuous cropping of these and on lighter 
soils this element should be included in the fertilizer. 

The Application of FertilizerH 

For plant cane, a small quantity of readily available 
fertilizer directly under and near the cane is highly 
beneficial, as it provides food also for the sucker, 
which, with food at hand, is greatly aided in develop- 
ing a healthy sucker, and thus the entire plant is given 
a vigorous send-off in youth. It is necessary, to 
give a good start to a young plant, to withhold manures 
until a stand is secured, though when cane is planted 
during the fall and winter, as it is in Louisiana, the 
danger of loss by leaching must be reckoned upon, and 
the exact amounts to be applied at that time regulated 
by the judgment of the planter. Usuallj' the more 
perfect the incorporation of a manure in the soil th^ 



PROPER APPLICATION 321 

better the results to be expected, but in this case it 
should be deposited in a drill and well mixed with the 
soil. In the spring, after the cane is closely off-barred, 
the fertilizer, if not applied at planting, should be 
scattered on both sides of the plant from the center of 
the row to the off-barred furrow. Hence, in reversing 
the furrow, the manure is covered, and subsequent culti- 
vation will mix the latter with the soil. If the cane has 
received the first application at planting, the second one 
should be given in May, on both sides of the row. 
The stubbie cane should not be fertilized very long 
before each sprout has sent out its own rootlets, since 
prior to this no good could be accomplished, and there 
would be a waste of manure. 

MISCELLANEOUS CROPS 

Other crops of importance for which the need of 
fertilizers is frequently apparent include sorghum, 
buckwheat, peanuts, roses and herbaceous plants, 
lawns, grasses, and plant-house vegetables. These 
are, of course, similar to those alreadj' described, 
since their best development requires that they shall 
be well supplied with the fertilizing constituents, 
nitrogen, phosphoric acid and potash, though their 
special needs in this respect have not been so fully 
investigated as the other crops dealt with in this 
chapter. The discussion of their requirements is, 
therefore, necessarily brief, and the suggestions made 
are of a general rather than a special character, though 
they may serve as a safe guide. 



322 FERTILIZERS 

Sorghtim 

Sorghum is growu both for forage and for sugar, 
and its fertilization should be discussed from these two 
standpoints. If grown for forage, the fertilization 
should be more liberal and of a different character 
than if for sugar, as the object is the largest yield of 
succulent food rather than the highest yield of sugar, 
and the yield of sugar is not always consistent with the 
highest yield of cane. For forage, therefore, the ferti- 
lizer recommended for maize forage (p. 242) is well 
adapted for sorghum on soils in a good state of fertility, 
though since the plant is very slow to start, its early 
growth is stimulated if a larger amount of readily 
available nitrogen is used than is desirable for corn, 
particularly on soils of medium fertility, and which 
have not been previously well fertilized. If grown for 
sugar, too much nitrogen must be avoided, since an 
excess of this element in the fertilizer causes an im- 
perfect ripening, and consequently a higher percent- 
age of non-crystallizable sugar in the cane ; though 
if quickly available forms are used, as nitrate, am- 
monia, or dried blood, which may be absorbed by the 
plant early in the season, a larger amount may be 
applied with safety than if the poorer forms are used. 
Of the three constituents, potash in the form of 
muriate seems to be the one exercising the greatest 
influence upon the yield of sugar, hence it should 
always be introduced in considerable amounts in fer- 
tilizers for sorghum.* A fertilizer furnishing 20 



•Report for 1886, New. lersey Agricultural Experiment Station. 



B UCKWHEA T 323 

pounds of nitrogen, 35 of phosphoric acid and 60 of 
potash per acre will meet the needs on average soils. 

Bucltwheat 

Buckwheat is frequently grown upon the poorer 
soils of the farm. It is a crop well adapted to moun- 
tain lands, and as a preparatory crop in the breaking 
of new lands. It has not been carefully studied in 
reference to its needs for plant -food, though phosphoric 
acid seems to be the constituent more particularly 
required than the others. Its need of nitrogen is 
marked, yet because its entire growth and development 
are made during the months of July and August, when 
conditions are most favorable for soil activities, heavy 
nitrogenous fertilization is not to be recommended, 
except when grown on very light soils, or those defi- 
cient in vegetable matter. The moderate use of fer- 
tilizers rich in minerals, and which contain nitrogen in 
quickly available forms, result favorably, not only in 
increasing the yield, but assist materially in maturiug 
the crop, a matter of great importance. A fertilization 
with 25 pounds per acre each of phosphoric acid and 
potash and 10 of nitrogen may be regarded as a good 
one for soils of medium character, 

Feanut 

The peanut is a leguminous plant, and, like others 
of this family, is not specifically benefited by nitrogen, 
but responds readily to liberal dressings of phosphoric 



/ 



324 FERTILIZERS 

acid and potash. The fertilization suggested for green 
manure crops, namely, a mixture of three parts acid 
phosphate and one part muriate of potash, or equal 
parts of acid phosphate and kainit, may be used for 
this crop with great advantage. The applications, if 
frequently made, need not exceed 300 to 400 pounds 
per acre. Like other leguminous crops, it is specifically 
benefited by lime, medium dressings of which (20 
bushels per acre) should be made at least once in four 
years. In the districts in which this crop is success- 
fully grown, lime marls are frequently obtainable at 
slight expense, and may be used with great advantage. 

Roses, and Other Flowering Plants 

In the growing of roses and other herbaceous 
plants, of which the flowers constitute the crop, great 
care is usually taken in the preparation of the soil, 
and natural soils are seldom used. Notwithstanding 
the richness of the prepared soils, the crops are bene- 
fited by the addition of commercial fertilizers, partic- 
ularly those phosphatic in their nature. Ground bone 
is especially useful, since it furnishes both nitrogen 
and phosphoric acid in slowly available forms, and 
usually sufficient nitrogen to meet the needs of the 
plant, as excessive quantities of this element cause a 
too vigorous aud rank growth of foliage, which is 
not accompanied by profuse flowering. A good mix- 
ture for the prepared soils, therefore, may consist 
of four parts of ground bone and one part of mu- 
riate of potash, which may be applied at the rate of 



FLOWERS AND LAWN^ 325 

four pounds per square rod of area, and well woi-ked 
into the soil previous to setting the plants. The after- 
fertilization may contain a larger portion of the sol- 
uble phosphoric acid, which is more readily distrib- 
uted. The need for nitrogen is indicated by a yel- 
low, rather than a bright green color in the foliage. 
Nitrogen may be supplied by light dressings (% to 1 
pound per square rod) of the active forms of this 
element, preferably nitrate of soda, because of its ready 
distribution. In the preparation of soils for theset 
plants in the house, the mixture may be applied at the 
rate of 2 pounds for every 100 square feet of surface, 
the after application to consist of the more soluble 
forms as recommended for the hardy plants. An even 
mixture of nitrate of soda and acid phosphate may be 
used at the rate of one pound for every 100 square feet 
of surface once in two weeks, if the plants do not 
show vigorous growth. 

Lawn Grasses 

The fertilization of lawns is also important in a 
sense, because proper fertilizing obviates the necessity 
of the home manures, which, although excellent as 
sources of the constituents, are frequently offensive. 
The use of manure also involves considerable labor, 
both in the application and the consequent removal 
of the coarse part in the spring, besides resulting in 
the introduction of weed seeds. In the preparation 
of the soil for a lawn, it must be supplied with an 
abundance of all of the necessary fertilizer ingredients 
previous to seeding, and of these phosphoric acid and 



326 fERTILIZEBS 

nitrogen are especially important. Too g^eat an ex- 
cess of potash encourages the development of the 
clovers rather than the grasses. This preparatory 
fertilizer may contain the more slowly available forms 
of nitrogen and phosphoric acid. Ground bone is an 
excellent source of these elements, and a mixture of 
five parts of ground bone and one of muriate of pot- 
ash makes an excellent dressing. This may be ap- 
plied at the rate of five pounds per square rod, and 
thoroughly worked into the soil. The after -fertiliza- 
tion may consist chiefly of nitrogen, preferably as a 
nitrate, since its ready solubility permits of its free 
penetration into the lower layers, which encourages 
a deeper root system, and thus greater resistance 
to drought. 

The top -dressings with nitrate of soda should con- 
sist of light fractional dressings, rather than of large 
amounts at one time. One -half pound per square 
rod, twice or thrice during the season — the first as 
soon as the grass is well started in the spring, and 
preferably immediately preceding a rain — will, if the 
land has been previously well prepared, be sufficient. 
To facilitate the distribution of the nitrate, as well as 
to supply a sufficient abundance of phosphoric acid, 
it may be mixed with equal parts of ground bone. 

Forcing -house Crops 

A rich garden loam, to which a considerable pro- 
portion of stable manure — one-third to one-half the 
bulk — has been added, is the usual type of soils 



VEGETABLUS UNDER GLASS 327 

tor such crops as tomatoes, lettuce, radishes and 
cucumbers under glass. The addition of fertilizers 
to these is seldom advisable. It has been demon- 
strated, however, that such mixtures are not essential, 
and that the crops may be profitably and successfully 
grown in mediums which contain no plant -food,* if 
supplied with an abundance in available forms from 
artificial sources. In the absence of good manure, 
which is the chief expense, a reasonably fertile loamy 
soil may be used for filling the beds, in which at the 
time of filling may be mixed, for each 100 square feet 
of surface, one -half pound of nitrate of soda, one 
pound of acid phosphate, one pound of ground bone, 
and one -half pound of muriate of potash. This appli- 
cation will be sufficient to supply the needs of the 
plants for food until growth is well started, after 
which they should be fertilized at least once each week 
with one -quarter of a pound of nitrate of soda for 
every 100 square feet of surface area, and with the 
mineral fertilizers at the rate of one pound of acid 
phosphate and one -half pound of muriate of potash 
every two weeks. These may be applied in solution, 
or evenly distributed over the surface of the soil, and 
worked in before watering. The amounts to apply 
should always be governed by the judgment of the 
grower. There is less danger from the application 
of too much, if properly used, than is commonly 
supposed. 



• C;onnectieut State Experiment Station Reports tor 1895, 1896 and 1897. 



INDEX 



Actual potash. See potash. 

Agricultural salt, 117. 

Agricultural value of a fertilizer, 
measured by value of increased crop 
produced, 152, and availability of its 
constituents, 153; distinct from com- 
mercial value, 153. 

Alfalfa, character of its growth, 252; 
its fertility content, 253; fertiliza- 
tion, 253. 

Ammonia, its formation in the soil, 
50; a better form than organic nitro- 
gen, 50; its commercial form, 50. 
See also sulfate of ammonia. 

Ammonite, its composition, 41; how 
obtained, 42. 

Analysis of fertilizers, how to inter- 
pret, 149; indicates whether fertilizer 
is high or low-grade, 149; does not 
always show the source of the ele- 
ments, 149. 

Animal matter. See ammonite. 

Apatite, G9. 

Apples, soil-exhaustion from growing 
290; fertilization, 2D 1-3; New York 
(Cornell) experiments, 290. 

Apricots, fertilization, 299. 

Artificial fertilizers, history of their 
use, 28; need of, 30; made necessary 
by increase in cost of labor, 30; by 
demands for special crops, 32; from 
inadequacy of farm manures, 33; by 
growing importance of fruitgrowing, 
34; will it pay to use them, 35; rea- 
sons for their unprofitable use, 36. 

Artificial fertilizer cartridges, 187. 

Ashes. See coal, cotton-hull, lime- 
kils, tan-bark and wood ashes. 



Asparagus, character of its gi-owth, 
264; conditions govering its sale, 
265; salt as a fertilizer for, 266; fer- 
tilization, 206-8. 

Availability of fertilizers. See under 
different fertilizing materials. 

Azotin,4l. 

Barley, substitution of, for oats in 
rotation, 207. 

Barley and peas, fertilization, 248. 

Basic slag, 70. 

Bat guano. See guano. [bean. 

Beans, fertilization, 270. See also soy 

Beets, character of growth, 270; ferti- 
lization, 271. See also fodder and 
sugar beets. 

Berries, cf , fruit crops and small fruits. 

Blackberries, fertilization, 302. 

Blood, dried, its characteristics, 40; 
how obtained, 40; red, 40; black, 
41; its composition, 41; the avail- 
ability of its nitrogen, 55. 

Bone-ash, how obtained, 66; its compo- 
sition, 66. 

Bone-black, how obtained, 65; its com- 
position, 66. 

Bone, dissolved. See superphosphates. 

Bone-meal, variations in its composi- 
tions, 60; meaning of fine bone, 61; 
its best use for soil-improvement 
and slow-growing crops, 63, 76; its 
nitrogen availability, 55; its phos- 
phoric acid availability, 75; its phos- 
phate more useful than that derived 
from mineral sources, 66, 73. 

Bone meal, raw, 60; its composition, 
61; objections to its use, 61. 



(329) 



330 



INDEX 



Bone meal, steamed, 61; its advan- 
tages, 62; its composition, 62. 

Bono pliosphate, iiow to convert into 
phosphoric acid, 134. See also phos- 
phate. 

Bono tankage, its agricultural value, 
64; its composition, 63. 

Bnissela sprouts, character of its 
growth, 272; fertilization, 273. 

Buckwheat, fertilization, 323; as green 
manure, 122. 

Cabbage, character of its growth, 272; 

fertilization, 273. 
Canadian apatite, 69. 
Carrots, fertilization, 258. 
Castor pomace, its composition and 

source, 47; the availability of its 

phosphoric acid, 65. 
Cauliflower, character of its growth, 

272; fertilization, 273. 
Celery, character of its growth, 275; 

fertilizatiou, 275. 
Cereals, character of their growth, 177; 

fertility content of, 17; fertilization, 

191 et seq.; as forage crops, 241. 
Chemical elements, needed in plant 

growth, 2; but insufficient by them- 

S(;lves, 4. 
Cherries, fertilization, 2&? 
Chicken manure, its compo.sl;ion and 

value, 104. 
Chili saltpetre. See nitrate of soda. 
Citrous fruits, fertilization, 299. 
Clay soils, thoir physical imperfec- 
tions, 171; usually need phosphhoric 

acid and lime, 170. 
Climate, its influence on soil fertility, 4. 
Clovers, character of their growth, 

178; fertilization, 203; as forage crop, 

249; as green manure, 120; requiio 

liberal supply of mineral elements, 

250. 
Coal ashes, 111. 
Commercial valuation of fertilizers, 

based ou commercial value of con- 



stituents, 155 ; schedule of valuos 
used in, 157 ; objections to, 1.59 ; 
advantages of, 161. 

Commercial value of fertilizers, deter- 
mined by trade conditions. 153; no 
measure of agricultural value, 155, 
158; calculation of, 162. 

Corn, character of its growth, 177, 199; 
fertility content of, 199; fertilization. 
200 ; fertilization for continuous 
growing, 208. 

Corn forage, 242; fertilization, 243. 

Corn silage, fertilization of com for, 
244. 

Corn, sweet, character of its growth. 
276 ; fertilization, 276. 

Cotton, character of its growth, 305: 
its fertUity content, 307; fertilira- 
tion, 307-11; Georgia and South Car- 
olina experiments, 309. 

Cotton-hull ashes, 112. 

Cotton-seed meal, its composition, 46; 
used also as a cattle feed, 46; its 
nitrogen availability, 05; its phos- 
phoric acid availability, 65. 

Cow pea, character of its growth, 251; 
fertilization, 252 ; as forage crop, 
251 ; as green manure, 120. 

Crab, king, its composition, 43; its 

Crimson clover, 120. [value, 107. 

Cucumbers, character of their growth, 
273; fertilization, 274,327. 

Currants, fertilization, 303. 

Denitrification, loss of fertility 

through, 11. 
Dicalcic phosphoric acid. See reverted 

phosphoric acid. 
Double manure salts. See salfat« of 

potash and magnesia. 

Egg-plant, character of its growth, 277; 

fertilization, 277. 
Experiments by the farmer hliuielf, 

their value, 193. 



INDEX 



331 



Farm labor, increase in cost of, 31. 

Farm manures, losses in, 19; inade- 
quate for demands of crops, 33. 

Farm practice, irrational, 18. 

Fertility, what constitutes it, 2j poten- 
tial, 2, 6 ; practical, 6 ; dependent 
upon usable potential fertility, 6; 
influenced by moisture, climate, sea- 
son, physical character of soil, 4, and 
culture, 10; loss of, by leaching 8, 
by drainage 10, 12, by denitrification 
11, by jaechanical means 13, by 
removal of crops 14; how to reduce 
its loss, 9. 

Fertility elements, prices received for 
them in different crops, 15 ; contained 
in mills 16, wheat 16, cereals and 
vegetables 17; their usefulness not 
dependent upon their source, 27. 

Fertilizers, losses in, 19; their func- 
tion, 21 ; essential manurial elements 
of, 21; their indirect effect, 21, 23; 
their direct effect, 23 ; effect of vege- 
table matter in, 22; distinction 
between manures and, 22 ; their 
value depends upon availability of 
essential constituents, 24; classifi- 
cation of, 124; chemical, 126; com- 
mercial, 124: high-grade vs. low- 
gi-ade, 128, 146; .cf. artificial ferti- 
lizers, analysis, purchase, use, and 
valuation of fertilizers. 

Fertilizers, complete, 138; advantages of 
purchasing, 140; disadvantages, 140. 

Fertilizers, incomplete, 138; advantages 
of purchasing, 139; disadvantages, 139. 

Fertilizers, mixed, 138; their uniform- 
ity, 164; conditions influencing their 
use and value, 1G5 tt seg. 

Fertilizer formulas, for cotton, 310; 
fruit crops, 288; potatoes, 216, 220, 
221; sweet potatoes, 224; tomatoes, 
233, 234. 

Fertilizing materials, standard or 
high-grade, 125; low-grade, 124. 127; 
Tariable in composition, 126. 



Fertilizing systems, based upon spe- 
cific influence of a single element, 
182; based upon necessity of abun- 
dant supply of the minerals, 184; based 
upon needs of plants as shown by 
chemical analysis, 186; where ferti- 
lizer is applied to money crop of 
rotation, 188; an irrational system, 
the "hit or miss," 189; in a grain and 
grass rotation, 198 et seg.; fertility 
gained by its use, 204; system should 
be modified if no farm manures are 
used, 206. 

Fish, dried, its source, 42; its composi- 
tion, 42; its nitrogen availability, 55; 
its phosphoric acid availability, 65. 

Fish scrap, crude, its composition and 

Florida phosphate, 68. (value, WZ. 

Flowers, fertilization of, 324. 

Fodder beets, fertilization, 258. 

Forage crops, cereals and grasses, 241; 
clovers and other legumes, 249 ; roots 
and tubers, 257; conditions of growth, 
241; as soiling crops, 254; New Jer- 
sey experiments, 249. 

Fruit crops, character of their growth, 
181; require fertilization, 282; differ 
from other farm crops, 283; func- 
tions of fertilizing elements with, 
284; influence of character of soil, 
285; fertilization, 287; a basic for- 
mula for, 288. 

Fruits, smaU, character of their 
growth, 300; fertilization, 301 et seq. 

Garbage tankage, 44. 

Gooseberries, fertilization, 303. 

Grapes, fertilization, 303. 

Grasses, character of their growth, 
178; fertilization, 203 et seq.,- contin- 
uous growing of, 210; as forage crops, 
241; for lawns, 325. 

Greenhouse crops, fertilization, 327. 

Green manures, meaning of, 118; legu- 
minous crops the most valuable for, 
118; conditions influencing their use. 



332 



INDEX 



Grepu manures, continued— 
119; croi)8 available as, 120; their 
value dependent chiefly upon their 
nitrogen-gathering capacity, 118 et 
SR<i.; prevent losses in fertility, 122. 
See alse foi-age crops. 

Guano, artifiei.il, inferior to the nat- 
ural product, 48; bat, 48; Ichaboe, 
48; Penivian, 47; phosphatic, its 
availability, 70, 77. 

Guarantee, its necessity, 129; required 
by law in most states, 130; sometimes 
misleading, 133 ; its interpretation, 
134 et seq. 

Gypsum, its composition, 115 ; its 
value, U6. 

Hair waste, 45, 104. 

Herbaceous crops, fertilization, 324. 

Home mixtures, their advantages, 141; 
care required in their preparation, 
141; formulas, high-grade and low- 
grade, Wletseq.; make- weight to be 
avoided, 140. 

Hoof meal, its composition, 42 ; its 
nitrogen availability, 55. 

Horn meal, its composition, 45 ; its 
nitrogen availability, 55. 

Ichaboe guano. See guano. 

Iron phosphate, 70. 

Irrational farm practice, 18, 189. 

Kainit, its composition, 94; its use, 95; 

preferable to muriate of potash on 

sweet potatoes. 225. 
King crab, 43, 107. 

Lawn grasses, fertilization, 325. 

Leather meal, 45; its nitrogen availa- 
bility, 55. 

Leguminous crops, most valuable as 
green-manure, 118; lime needed by, 
254. See also clovers, cow peas and 
soy beau3. 



Lemons, fertilization, 299. 

Lettuce, character of its growth, 277; 

fertilization, 277, 327. 
Liebig's organic chemistry, etc., 28. 
Lime, its source, 113; its composition, 

114 ; quick-lime, 114 ; marble, 114 ; 

oyster shell, 114: gas, 115; care needed 

in its use, 115; its value, 114 et seq.; 

needed by legumes, 254; its action on 

fruit-crops, 285. 
Lime-kiln ashes, 110. 
Linseed meal, its composition, 46; 

used also as a cattle-feed, 4fl. 
Lobster shells, 108. 
Lucerne. See alfalfa. 

Maize. See corn. 

Make-weight in fertilizers, cost of 
handling, 140. 

Manures. See fertilizers and green- 
manures. 

Market-garden crops, character of 
their growth, 180, 262; fertilization, 
204; a basic fertilizer for, 267. 

Marl, its composition, 112; soil im- 
proved by its use, 113. 

Meadows, fertilization, 211. 

Meat, dried. See ammonite. 

Milk, fertility content of, 16. 

Millet, fertilization, 249; fertility con- 
tent of, 249. 

Moisture. See water. 

Monoealeic phosphoric acid. See solu- 
ble phosphoric acid. 

Muck, its composition, 106; used as a 
source of humus, 106; how secured, 
107. 

Muriate of potash, its composition, 
90; its bad effects on tobacco and 
sugar-beets, 94 ; how to convert into 
.actual potash, 134. 

Muskmelons, character of their growth, 
273; fertiliz.ition, 274. 

Mussels, their composition and vaiua, 
107. 

Mustard, as a green-manure, 122. 



INDEX 



333 



Nitrate of soda, its source, 52; its com- 
position and value, 52 ; its availa- 
bility, 53; compared with sulfate 
of ammonia, 53 ; how to convert 
into nitrogen, 134; valuable as fer- 
tilizer for tomatoes, 227. 

Nitrogen, its action on fruit crops, 284; 
its availability 53 et seq., how esti- 
mated 54, modified by crop 53, season 
55, and object of use 56; of the air 
available to leguminosaa, 38; how to 
convert into ammonia, 134; exists in 
the air, 38; its different forms, 25, 39 
etseg.; its illusiveness, 8; important 
because easily lost and expensive, S; 
conditions determining its loss, 9; 
loss by drainage 10, by escape as 
gas 11, by leaching 9; necessary for 
plant growth, 3 ; nitrate the most 
valuable form, 52; organic, 39 et seq.; 
its availability, 54; its sources, 38; 
its unstability, 8; how it is used by 
the plant, 50, 52. 

Oats, character of its growth, 177; 
fertilization, 201; continuous grow- 
ing of, 209 ; pouting period in its 
growth, 247. 

Oats and peas, fertilization, 248. 

Oats forage, fertilization, 247. 

Onions, character of their growth, 278; 
fertilization, 280. 

Onion sets. See onions. 

Oranges, fertilization, 299. 

Organic nitrogen, what it is, 39; its 
forms, 40 et seq.; its availability, 54. 

Peaches, need and advantages of fer- 
tilization, 294; methods of, 297; New 
Jersey experiments, 294. 

Peanuts, fertilization, 324. 

Pears, fertilization, 291-3. 

Peas, fertilization, 270; see also barley 
and oats. 

Peat. See muck. 

Peruvian guano. See 8:nano. 



Phosphate of lime in bones, 60. 

Phosphates, correct and false use of 
the term, 58 ; animal, 59 et seq.; 
mineral, 66 et seq.; South Carolina 
rock, 67; Florida, 68; Canadian apa- 
tite, 69; Tennessee, 69; iron 70, its 
availability 76; how used by plants, 
71; insoluble in water, 72; useful- 
ness depends upon rate of decay, 
72; availability depends upon their 
source 72, fineness of division 73, 
character of soil 74, and kind of crop 
74; different from superphosphates, 
83, See also bone meal. 

Phosphate slag, 70. 

Phosphoric acid, necessary for plant 
growth, 3; its loss through drainage, 
12; its different forms, 25; insoluble, 
78; soluble, 79; chemically identical 
independent of its source, 82 ; re- 
verted 80, theory of its formation 85, 
its value 86; tetra-calcic, 80; mean- 
ing of available, 88; remains in soil 
until removed by plants, 90; its fixa- 
tion in the soil, 01; how to convert 
into bone-phosphate, 134; its action 
on fruit crops, 2,-;5. 

Pigeon manure, 49, 105; its inferiority 
to natural guanos, 49. 

Plant-food, available, 24; unavailable, 
34; necessity of adding more than is 
required by definite increase of crop, 
205; loss from use of soluble, 26; 
cf. fertilizers. 

Plants, vary in power of acquiring 
food, 177. 

Plot experiments, scheme for, 194; 
their interpretation, 196; their value, 
190; results of, 197. 

Plums, fertilization, 299. 

Potash, necessary for plant growth, 3; 
its loss through drainage, 13; its dif- 
ferent forms, 25. 93; its importance, 
92; importance of form, 93; its fixa- 
tion in the soil, 98; how to convert 
actual into muriate and sulfate, 134; 



334 



INDEX 



Potash, continued- 
its action on fmit crops, 284 ; see 
also kainit, sylvinit, muriate and 
sulfate of potash. 

Potash salts, their occurrence, 92; their 
uniformity of price, 92. 

Potatoes, fertility content of, 21.5; fer- 
tilization for early, 215 et seq.; fer- 
tiliration for late, 220; sulfate of 
potash improves their quality, 219; 
importance of form of fertilizins 
elements, 219; New York (Geneva) 
experiments, 215, 218. 

Poultry manure, 49, 104; its composi- 
tion, 104. 

Powder waste, 117. 

Pumpkins, character of their growth, 
273; fertilization, 274. 

Purchase of fertilizers, the unit basis 

128, its advantages 129; the ton basis, 

129, its defects, 129; law not sufficient 
for protection, 130; intelligence 
needed, 131; cooperative, 148; meth- 
ods of 138, by buying raw materials 
138, by buying mixed brands 138, 
advantages and disadvantages of 
each method, 138. 

Rape, fertilization, 260. 

Raspberries, fertilization, 302. 

Rhubarb, character of its growth, 277; 
fertilization, 278. 

Root crops, character of their growth, 
179; fertility content of, 258; ferti 
lizRtion, 258. 

Roses, fertilization, 324. 

Rye, as green manure, 122; as substi- 
tute for wheat in rotation, 207; fertili- 
zation for continuous growing, 209. 

Rye forage, fertilization, 245, 246. 

Sftsdy soils, their physical Imperfec- 
tions, 170; usually need potash, 170. 

Scallions, character of their growth, 
279; fertilization, 280. 

Season, its influence on soil fertility, 4. 



Sea weed, 108. 

Sewage, its composition and value, 105. 

Soda, nitrate of. See nitrate. 

Soil fertility, its importance, 1; what 
constitutes, 1; influenced by moist- 
ure, climate and season, 4; qualified 
by location of soil, 5. 

Soiling crops, scheme for, 255; New 
Jersey experiments, 256. 

Soils, influence of physical character 
of, 4; their derivation a guide as to 
deficiencies, 168. See clay and sandy 
soils. 

Sorghum, fertilization, when grown for 
forage and for sugar, 322. 

South Carolina rock. See phosphate 
and superphosphate. 

Soy bean, as forage crop, 120, 251; 
character of its growth, 251 ; fer- 
tilization, 251. 

Spinach, character of its growth, 277; 
fertilization, 277. 

Sprouts. See Brussels sprouts. 

Squashes, character of their growth, 
273 ; fertilization, 274. 

Strawberries, fertilization, 301. 

Sugar-beets, fertility content of, 236; 
fertilization when grown for sugar 
237, when grown for fodder, 258 ; 
effect of previous deep cultivation 
on. 239. 

Sugar-cane, fertility content of, 318 ; 
fertilization, 318; Louisiana experi- 
ments, 317. 

Sulfate of ammonia, its composition, 
51; its source, 51; advantages of its 
use, 51 ; its availability, 53 ; com- 
pared with nitrate of soda, 53; how 
to convert into nitrogen, 134. 

Sulfate of lime. See gypsum. 

Sulfate of potash, its composition, 07; 
preferable to muriate for some crops, 
94, 219; how to convert into actual 
potash, 134. 

Sulfate of potash and magnesia, its 
composition, 97. 



INDEX 



335 



Superphosphates, how made, 80; dif- 
ferences due to source, 81, 8:!; differ- 
ent from phosphates, 83; bone, 83, 
88; mineral, 84, 88; double, 87, 89; 
their composition, 88 ; bone-black, 
88 ; South Carolina rock, 88 ; Florida, 
89; Tennessee, 89 : should contain no 
free acid, 89. 

Swedes, fertilization, 260. 

Sweet potatoes, quality an important 
factor in, 221; fertility content of, 
222; fertilization, 222 *£ «f 7..- Georeia 
experiments, 223; New Jersey experi- 
ments, 223, 226. 

Sylvinit.'its composition, 95; its use, 
96. 

Tan-bark ashes, their composition, 110. 

Tankage, its source, 43 ; its composi- 
tion, 44; concentrated, 43; its varia- 
bility, 44; its nitrogen availability, 55; 
see also bone and garbage tankage. 

Tennessee phosphate. See phosphate. 

Tetra-calcic phosphoric acid. See 
phosphoric acid. 

Thomas phosphate meal. See iron 
phosphate. 

Timothy, character of its growth, 178 ; 
fertilization, 203. 

Tobacco, fertility content of, 312; 
effect of fertilizers on quality, 312; 
injurious effect of chlorids, 315 ; fer- 
tilization, 313 et seq.; Connecticut 
experiments, 313. 

Tobacco stems, their composition, 100 ; 
their value, 101. 

Tomatoes, fertilization for early, 227, 
for late, 231 ; composition of vine, 
333 ; composition of fruit, 233 ; 



nitrate of soda as fertilizer for, 227, 
235 ; New Jersey experiments. 226. 

Tri-calcic phosphoric acid. See insolu- 
ble phosphoric acid. 

Tuber crops, for forage, 201. 

Turnips, fertilization, 260, 271 ; char- 
acter of their growth, 270. 

Unit system of purchase, 128. 

Use of fertilizers, object of, 167 ; 
conditions modifying, 167 et seq.: 
knowledge of nature of soil neces- 
sary in, 170; influence of previous 
treatment and cropping on, 172 ; 
influence of character of crop, 175 ; 
influence of method of farming, 176 ; 
importance of system in, 198. 

Valuation of fertilizers. See commer- 
cial valuation. 

Vegetable matter in manures, its effect 
on physical character and absorptive 
power of soils, 22. 

Vegetables, fertility content of, 17. 

Ville's system of fertilization, 182. 

Waste from phosphorus works, 116. 

Water, its influence on soil fertility, 4. 

Watermelons, character of their 
growth, 273 ; fertilization, 274. 

Wheat, fertility content of, 16, 192; 
character of its growth, 177 ; fer- 
tilization 202, for continuous grow- 
ing of, 208. 

Wheat forage, fertilization, 245. 

Wood ashes, their composition, 109; 
valuable source of potash. 110. 

Wood waste, 45 ; its composuion, 103; 
its nitrogen availability, 55. 



T 



WOWKS BY PROFESSOR BAILEY 

HE SURVIVAL OF THE UNLIKE: 

A Collection of Evolution Essays Suggested 
by the Study of Domestic Plants. By L. H. 
BAILEY, Professor of Horticulture in the Cornell 
University. 

rOURTH EDITION— CIS PACES — 22 ILLUSTRATIONS — tS.OO 

To those interested in the underlying philosophy 
of plant life, this volume, written in a most enter- 
taining style, and fully illustrated, will prove wel- 
come. It treats of the modification of plants under 
cultivation upon the evolution theory, and its atti- 
tude on this interesting subject is characterized 
by the author's well-known originality and inde- 
pendence of thought. Incidentally, there is stated 
much that will be valuable and suggestive to the 
working horticulturist, as well as to the man or 
woman impelled by a love of nature to horticul- 
tural pursuits. It may well be called, indeed, a 
philosophy of horticulture, in which all interested 
may find inspiration and instruction. 

The Survival, of the Unlike comprises thirty essays touching 
upon The General Fact and Philosophy of Evolution (The Plant 
Individual, Experimental Evolution, Coxey's Army and the Russian 
Thistle, Recent Progress, etc.); Expounding the Fact and Causes of 
Variation (The Supposed Correlations of Quality in Fruits, Natural 
History of Synonyms, Reflective Impressions, Relation of Seed- 
bearing to Cultivation, Variation after Birth, Relation between 
American and Eastern Asian Fruits, Horticultural Geography, Prob- 
lems of Climate and Plants, American Fruits, Acclimatization, Sex 
ia Fi-uits, Novelties, Promising Varieties, etc. ) ; ar.d Tracing the 
Evolution of Particular Types of Plants (the Cultivated Strawberry, 
Battle of the Plums, Grapes, Progress of the Caruation. Petunia., 
The Qardttn Tomato, etc.). 



T 



WORKS BY PROFESSOR BAILEY 

HE EVOLUTION OF OUR NA* 

TIVE FRUITS. By L. H. BAILEY, Pro- 
fessor of Horticulture in the Cornell University. 

*t» PACES— I2S ILLUSTRATIONS — tZ-OO 

In this entertaining volume, the origin and de- 
velopment of the fruits peculiar to North America 
are inquired into, and the personality of those horti- 
cultural pioneers whose almost forgotten labors 
have given us our most valuable fruits is touched 
upon. There has been careful research into the 
history of the various fruits, including inspection 
of the records of the great European botanists who 
have given attention to American economic botany. 
The conclusions reached, the information presented, 
and the suggestions as to future developments, can- 
not but be valuable to any thoughtful fruit-grower, 
while the terse style of the author is at its best in 
his treatment of the subject. 

The Evolution of our Native Fruits discusses The Rise of 
the American Grape (North America a Natural Vineland, Attempts 
to Cultivate tlie European Grape, The Experiments of the Dufours, 
The Branch of Promise, John Adlum and the Catawba, Rise of 
Commercial Viticulture, Wliy Did the Early Vine Experiments Fail ! 
Synopsis of the American Grapes) ; The Strange History of the Mul- 
berries (The Early Silk Industry, The "Multicaulis Craze,") ; Evolu- 
tion of American Plums and Cherries (Native Plums in General, 
The Chickasaw, Hortulana, Marianna and Beach Plum Groups, 
Pacific Coast Plum, Various Other Types of Plums, Natvve Cherries, 
Dwarf Cherry Group) ; Native Apples (Indigenous Species, Amelio- 
ration has begun); Origin of American Raspberry-growing (Early 
American History, Present Types, Outlying Types) ; Evolution of 
Blackberry and Dewberry Culture (The High-bush Blackberry an(S 
Its Kin, The Dewberries, Botanical Names); Various Types of 
Berry-like Fruits (The Gooseberry, Native Currants, Juneberry, 
Buffalo Berry, Elderberry, High-bush Cranberry, Cranberry, Straw- 
berry); Various Types of Tree Fruits (Persimmon, Custard- Apple 
Tribe, Thorn-Apples, Nut-Fruits) ; General Remarks on the Improve- 
ment of our Native Fruits (What Has Been Done, What Probably 
Should Be Done). 



THE RURAL SCIENCE SERIES 

Includes books which state the underlying principles 
of agriculture in plain language. They are suitable 
for consultation alike by the amateur or professional 
tiller of the soil, the scientist or the student, and are 
freely illustrated and finely made. 

The following volumes are now ready: 

THE SOIL. By P. H. King, of the University of Wisconsin. 303 pp. 45 
illustrations. ' 

THE FERTILITY OF THE LAND. By I. P. Roberts, of Cornell Univer- 
sity. 421 pp. 45 illustrations. 

THE SPRAYING OF PLANTS. By E. G. Lodeman, late of Cornell Uni- 
versity. 399 pp. 92 illustrations. 

MILK AND ITS PRODUCTS. By H. H. Wing, of ComeU University. 
311 pp. 43 illustratious. 

THE PRINCIPLES OF FRUIT-GROWING. By L. H. Bailey. 516 pp. 
120 illustrations 

BUSH-FRUITS. By F. W. Card, of Rhode Island College of Agricultnro 
and Mechanic Arts. 537 pp. 113 illustrations. 

FERTILIZERS. By E. B. Voobhees, of New Jersey Experiment Station. 
332 pp. 

THE PRINCIPLES OF AGRICULTURE. By L. H. Bailey. 300 pp. 92 
illustrations. 

IRRIGATION AND DRAINAGE. By F. H. King, University of Wiscongin. 
502 pp. 163 illustrations. 

THE FARMSTEAD. By I. P. Roberts. 350 pp. 138 illustrations. 

RURAL WEALTH AND WELFARE. By George T. Pairchild, Ex-Presi- 
dent of the Agricultural College of Kansas. 381 pp. 14 charts. 

THE PRINCIPLES OF VEGETABLE-GARDENING. By L. H. Bailey. 
468 pp. 144 illustrations. 

THE FEEDING OF ANIMALS. By W. H. Jordan, of New York State 
Experiment Station. 450 pp. 

FARM POULTRY. By George C. Watson, of Pennsylvania State College. 
341 pp. 

THE FARMER'S BUSINESS HANDBOOK. By I. P. Roberts, of CorneU 
University. 300 pp. 

THE CARE OF ANIMALS. By Nilson S. Mayo, of Kansas State ABii- 
cultural (College. 458 pp. 

THE HORSE. By I. P. Roberts, of Oornell University. 413 pp. 

New volumes will be added from time to time to 
the Rural Science Series. The following are in 
preparation: 

PHYSIOLOGY OP PLANTS. By J. Arthur, Purdue University, 

THE PRINCIPLES OP STOCK BREEDING. By W. H. Brewbe. of Yala 

University. 
PLANT PATHOLOGY. By B. T. Galloway and associates, of U. S. Depart 

ment of Agrlcultare. 
THE POME FRUITS (Apples, Pears, Quinces). By L. H. Baxubt. 



THE GARDEN -CRAFT SERIES 

Comprises practical handbooks for the horticultur- 
ist, explaining and illustrating in detail the various 
important methods which experience has demon- 
strated to be the most satisfactory. They may be 
called manuals of practice, and though all are pre- 
pared by Professor Bailey, of Cornell University, 
they include the opinions and methods of success- 
ful specialists in many lines, thus combining the 
results of the observations and experiences of nu- 
merous students in this and other lands. They are 
written in the clear, strong, concise English and in 
the entertaining style which characterize the author. 
The volumes are compact, uniform in style, clearly 
printed, and illustrated as the subject demands. 
They are of convenient shape for the pocket, and 
are substantially bound in flexible green cloth. 

THE HORTICULTURIST'S RULE BOOK. By L. H. Baiioit. 312 pp. 
THE NURSERY-BOOK. By L. H. Bailey. 36o pp. 152 iUustrationa. 
PLANT-BREEDING. By L. H. Bailky. 293 pp. 20 illustrations. 
THE FORCING-BOOK. By L. II. Bailky. 2G6 pp. S8 illustrations. 
GARDEN-MAKING. By L. H. Bailey. 417 pp. 250 illustrations. 
THE PRUNING-BOOK. By L. H. Bailky. 545 pp. 331 lUustrationa. 

THE PRACTICAL GARDEN-BOOK. By C. E. Hukk and L. H. Bailbv. 

250 pp. Many marginal outs. 



WORKS BY PROFESSOR BAILEY 

*HE CYCLOPEDIA OF AMERICAN 
HORTICULTURE : By l. h. bailey, of 

Cornell University, assisted by WILHELM MILLER, 
and many expert cultivators and botanists. 

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This great work comprises directions for the cul- 
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and ornamental plants known to be in the market in 
the United States and Canada. "It has the unique 
distinction of presenting for the first time, in a care- 
fully arranged and perfectly accessible form, the best 
knowledge of the best specialists in America upon 
gardening, fruit-growing, vegetable culture, forestry, 
and the like, as well as exact botanical information. 
. . . The contributors are eminent cultivators or 
specialists, and the arrangement is very systematic, 
clear and convenient for ready reference." 

" We have here a work which every ambitious gardener will wish to plaea 
on his sheif beside his Nicholson and his Loudon, and for such users of it a 
too advanced nomenclature would have been confusing to the last decree. 
With the safe names here given, there is little liability to serious perplexity. 
There is a growing impatience with much of the controversy concerning; 
revision of names of organisms, whether of plants or animals. Those in- 
vestigators who are busied with the ecological aspects of organisms, and 
also those who are chiefly concerned with the application of plants to the 
arts of agricxilture, horticulture, and so on, care for the names of organisms 
under examination only so far as these aid in recognition and identification. 
To introduce unnecessary confusion is a serioxis blunder. Professor Bailey 
has avoided the risk of confusion. In short, in range, treatment and edit- 
ing, the Cyclopedia appears to be emphatically useful ; . . . a work worthy 
of ranking by the side of the Century Dictionary." — The Nation. 

This work is sold only by subscription, and terms aad 
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c 



VOLUME I — READY SHORTLY 

YCLOPEDIA OF AMERICAN 

AGRICULTURE. Edited by PROF. L. H. 
BAILEY, of Cornell University, Editor of "Cyclope- 
dia of American Horticulture"; author of "Plant 
Breeding," "Principles of Agriculture," etc. 

WITH 100 FULI.-PACE PLATES AND ABOUT 2,S00 ILLUSTRATIONS 
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TENTATIVE SYNOPSIS OF CONTENTS 
VOLUME I 

Paet I— General, Con'SIDKRAtions— Agricultural Regions— Farm Industrie* 
— Layout of a Farm— Equipment and Capital Required— Farm Buildings 
Farm Water Works — Farm Machinery— Adornment of Farm Premises— 

Part II— Climatology— General Definition and Scope— Atmosphere— Tem- 
perature — Pressure— Circulation— Atmospheric Moisture— Storms— Pre- 
cipitation— Wen ther— Climate. 

Part III— Thk Soil— General Considerations— Oriein and Formation— Kinds 
and Characteristics— Properties— Germ Life in the Soil— Moisture— Til- 
lage — Fertilizers— Waste and Renovation — Soil Surveys. 

VOLUME II -FARM CROPS 

Part I— Plant Production— The Plant— Environment— Plant Improvement 
— Farm Management — Plant Introduction — Classifications— Industries. 

Part II— Individual Farm Crops (suggested treatment) — General— Geo- 
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ties — Flarvesting and Preservation— Uses and Preparation for Use — Man- 
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TIMBER CROP (Farm Woodlot) 

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Sj'stems of Forest Cropping— Improving and Caring for Crop — How to 
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and Hygiene — Products— Diseases and Disabilities— Judging and Scoring 
— Marketing— Exhibiting— History. 

Part III— Animal Industries or Technolooy— Dairying— Dressing and 
Curing of Meats— Storage— Refrigeration— Fertilizer Manufacture. 

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yoRKS "BY PworessoK bailey 

ESSONS WITH PLANTS: Surges- 
tions for Seeing and Interpreting Some of 
the Common Forms of Vegetation. By L. 
H. BAILEY, Professor of Horticulture in the Cornell 
University, with delineations from nature by W, S. 
HOLDSWORTH, of the Agricultural College of 
Michigan. 

SFCOND eOlTION— 48t PACKS— 446 ILLUSTRATIONS— tC HO— 
OLOVH-'SI.IO NET 

There are two ways of looking at nature. The 
old way, which you have found so unsatisfactory, 
was to classify everything — to consider leaves, roots, 
and whole plants as formal herbarium specimens, 
forgetting that each had its own story of growth 
and development, struggle and success, to tell. 
Nothing stifles a natural love for plants more effect- 
ually than that old way. 

The new way is to watch the life of every grow- 
ing thing, to look upon each plant as a living 
creatu4:*e, whose life is a story as fascinating as the 
story of any favorite hero. "Lessons with Plants" 
is a book of stories, or rather, a book of plays, for 
we can see each chapter acted out if we take the 
trouble to look at the actors. 

" I have spent some time in most delightful examination of it, and the 
longer I look, the better I like it. I find it not only full of interest, but 
eminently suggestive. I know of no book which begins to do so much to 
open the eyes of the student —whether pupil or teacher — to the wealth of 
meaning contained in simple plant forms. Above all else, it seems to be 
full of suggestions that help one to learn the language of plants, so they 
may talk to him."— Dabwin L. Babdwell, Superintendent of Schoolt, Bing- 
hamlon. 

"It Is an admirable book, and cannot fail both to awaken interest in 
the subject, and to serve as a helpful and reliable guide to young students 
of plant life. It vrill, I think, fill an important place in secondary schools, 
and comes at an opportune time, when helps of this kind are needed and 
MMisrly sought."— Professor V. M. Spaldinu, Universitv of Michigan, 

FIRST LESSONS WITH PLANTS 

An Abridgement of the above. 117 pages — 116 illustra> 
tions^— 40 cents neU 



WORKS aV PKOFE8SOR BAtLEY 



B 



OTANY : An Elementary Text for Schools. 

By L. H. BAILEY. 

sae PAce*— coo illustrations— at. lo nct 



"ThiB book is made for the pupil: ' Lessons With Plants * 
was made to supplement the work of the teacher." This is tha 
opening sentence of the preface, showing that the book is a 
companion to "Lessons With Plants," which has now become a 
standard teacher's book. The present book is the handsomest 
elementary botanical text-book yet made. The illustrations 
illustrate. They are artistic. The old formal and unnatural 
Botany is being rapidly outgrown. The book disparages mere 
laboratory work of the old kind: the pupil is taught to see things 
as they grow and behave. The pupil who goes through this book 
will understand the meaning of the plants which he sees day 
by day. It is a revolt from the dry-as-dust teaching of botany. 
It cares little for science for science' sake, but its point of view 
is nature-study in its best sense. The book is divided into four 
parts, any or all of which may be used in the school: the plant 
itself; the plant in its environment; histology, or the minute 
structure of plants; the kinds of plants (with a key, and de- 
scriptions of 300 common species). The introduction contains 
advico to teachers. The book is brand new from start t« 
finish. 

"An exceedingly attraetire textbook."— irfucatimiaJ BenUv. 
"It is a school book of the modem methods."— Tft* Dial. 

"It wonld be h:ird to find a better manual for sfhools or for intt- 
visual use."— r/te Outlook. 



THE MACMILLAN COMPANY 
64-66 Fifth Avenue NEW YORK 



JUL 2 1907 




LIBRAKV OF CONGRESS 



